smartctl

SMARTCTL(8)                 SMART Monitoring Tools                 SMARTCTL(8)

NAME
       smartctl - Control and Monitor Utility for SMART Disks

SYNOPSIS
       smartctl [options] device

DESCRIPTION
       [This man page is generated for the Linux version of smartmontools.  It
       does not contain info specific to other platforms.]

       smartctl controls the Self-Monitoring, Analysis and Reporting  Technol-
       ogy  (SMART)  system  built into most ATA/SATA and SCSI/SAS hard drives
       and solid-state drives.  The purpose of SMART is to monitor the  relia-
       bility  of  the hard drive and predict drive failures, and to carry out
       different types of drive self-tests.  smartctl also supports some  fea-
       tures  not  related  to  SMART.  This version of smartctl is compatible
       with ACS-3, ACS-2, ATA8-ACS, ATA/ATAPI-7  and  earlier  standards  (see
       REFERENCES below).

       smartctl also provides support for polling TapeAlert messages from SCSI
       tape drives and changers.

       The user must specify the device to be controlled  or  interrogated  as
       the  final argument to smartctl.  The command set used by the device is
       often derived from the device path but may need help with the '-d'  op-
       tion  (for  more information see the section on "ATA, SCSI command sets
       and SAT" below).  Device paths are as follows:

       LINUX:   Use the forms "/dev/sd[a-z]" for  ATA/SATA  and  SCSI/SAS  de-
                vices.   For SCSI Tape Drives and Changers with TapeAlert sup-
                port use the devices "/dev/nst*" and  "/dev/sg*".   For  disks
                behind  3ware  controllers  you  may  need  "/dev/sd[a-z]"  or
                "/dev/twe[0-9]", "/dev/twa[0-9]" or "/dev/twl[0-9]":  see  de-
                tails  below.   For  disks  behind  HighPoint  RocketRAID con-
                trollers you may need "/dev/sd[a-z]".  For disks behind  Areca
                SATA  RAID  controllers,  you  need  "/dev/sg[2-9]" (note that
                smartmontools interacts with the Areca controllers via a  SCSI
                generic  device  which  is different than the SCSI device used
                for reading and writing data)!  For HP Smart Array  RAID  con-
                trollers,  there are three currently supported drivers: cciss,
                hpsa, and hpahcisr.  For disks accessed via the  cciss  driver
                the  device  nodes are of the form "/dev/cciss/c[0-9]d0".  For
                disks accessed via the hpahcisr and hpsa drivers,  the  device
                nodes  you  need are "/dev/sg[0-9]*".  ("lsscsi -g" is helpful
                in determining which scsi generic device node  corresponds  to
                which  device.)   Use the nodes corresponding to the RAID con-
                trollers, not the nodes corresponding to logical drives.   See
                the  -d option below, as well.  Use the forms "/dev/nvme[0-9]"
                (broadcast  namespace)  or  "/dev/nvme[0-9]n[1-9]"   (specific
                namespace 1-9) for NVMe devices.

       if  '-'  is specified as the device path, smartctl reads and interprets
       it's own debug output from standard input.  See '-r ataioctl' below for
       details.

       smartctl  guesses  the device type if possible.  If necessary, the '-d'
       option can be used to override this guess.

       Note that the printed output of smartctl displays most numerical values
       in  base  10 (decimal), but some values are displayed in base 16 (hexa-
       decimal).  To distinguish them, the base 16 values are always displayed
       with  a  leading  "0x", for example: "0xff".  This man page follows the
       same convention.

OPTIONS
       The options are grouped below into several categories.   smartctl  will
       execute  the  corresponding  commands  in  the  order: INFORMATION, EN-
       ABLE/DISABLE, DISPLAY DATA, RUN/ABORT TESTS.

       SHOW INFORMATION OPTIONS:

       -h, --help, --usage
              Prints a usage message to STDOUT and exits.

       -V, --version, --copyright, --license
              Prints version, copyright, license, home page and  SVN  revision
              information for your copy of smartctl to STDOUT and then exits.

       -i, --info
              Prints the device model number, serial number, firmware version,
              and ATA Standard version/revision information.  Says if the  de-
              vice  supports  SMART,  and if so, whether SMART support is cur-
              rently enabled or disabled.   If  the  device  supports  Logical
              Block  Address mode (LBA mode) print current user drive capacity
              in bytes.  (If drive has a user protected area reserved,  or  is
              "clipped",  this may be smaller than the potential maximum drive
              capacity.)  Indicates if the drive is in the smartmontools data-
              base  (see  '-v'  options below).  If so, the drive model family
              may also be printed.  If '-n'  (see  below)  is  specified,  the
              power mode of the drive is printed.

              [NVMe]  For  NVMe  devices  the information is obtained from the
              Identify Controller and the Identify Namespace data structure.

       --identify[=[w][nvb]]
              [ATA only] Prints an annotated  table  of  the  IDENTIFY  DEVICE
              data.   By  default, only valid words (words not equal to 0x0000
              or 0xffff) and nonzero bits and bit fields  are  printed.   This
              can be changed by the optional argument which consists of one or
              two characters from the set 'wnvb'.  The character  'w'  enables
              printing  of all 256 words.  The character 'n' suppresses print-
              ing of bits, 'v' enables printing of all bits from valid  words,
              'b'  enables  printing  of all bits.  For example '--identify=n'
              (valid words, no bits) produces the shortest output and '--iden-
              tify=wb' (all words, all bits) produces the longest output.

       -a, --all
              Prints all SMART information about the disk, or TapeAlert infor-
              mation about the tape drive or changer.  For ATA devices this is
              equivalent to
              '-H -i -c -A -l error -l selftest -l selective'
              and for SCSI, this is equivalent to
              '-H -i -A -l error -l selftest'.
              For NVMe, this is equivalent to
              '-H -i -c -A -l error'.
              Note  that  for ATA disks this does not enable the non-SMART op-
              tions and the SMART options which require support for 48-bit ATA
              commands.

       -x, --xall
              Prints  all  SMART  and  non-SMART information about the device.
              For ATA devices this is equivalent to
              '-H -i -g all -g wcreorder -c -A -f  brief  -l  xerror,error  -l
              xselftest,selftest  -l  selective -l directory -l scttemp -l sc-
              terc -l devstat -l defects -l sataphy'.
              and for SCSI, this is equivalent to
              '-H -i -g all -A -l error -l selftest -l background -l sasphy'.
              For NVMe, this is equivalent to
              '-H -i -c -A -l error'.

       --scan Scans for devices and prints each device name, device  type  and
              protocol  ([ATA]  or  [SCSI])  info.  May be used in conjunction
              with '-d TYPE' to restrict the scan to  a  specific  TYPE.   See
              also info about platform specific device scan and the DEVICESCAN
              directive on smartd(8) man page.

       --scan-open
              Same as --scan, but also tries to open each device before print-
              ing device info.  The device open may change the device type due
              to autodetection (see also '-d test').

              This option can be used to create a draft smartd.conf file.  All
              options  after '--' are appended to each output line.  For exam-
              ple:
              smartctl --scan-open -- -a -W 4,45,50 -m admin@work > smartd.conf

              Multiple '-d TYPE' options may be specified with '--scan[-open]'
              to combine the scan results of more than one TYPE.

       -g NAME, --get=NAME
              Get  non-SMART  device settings.  See '-s, --set' below for fur-
              ther info.

       RUN-TIME BEHAVIOR OPTIONS:

       -j, --json[=cgiosuv]
              [NEW EXPERIMENTAL SMARTCTL FEATURE] Enables JSON output mode.

              The output could be modified or enhanced by the  optional  argu-
              ment  which  consists  of  one  or  more characters from the set
              'cgiosuv':
              'c': Outputs compact format without extra spaces  and  newlines.
              By default, output is pretty-printed.
              'g':  Outputs  JSON structure as single assignments to allow the
              usage of grep.  Each assignment reflects the absolute path of  a
              value.  The syntax is compatible with gron:
              'json.KEY1[INDEX2].KEY3 = VALUE;'.
              'o':  Includes the full original plaintext output of smartctl as
              a JSON array 'smartctl.output[]'.
              's': Outputs JSON object elements sorted by  key.   By  default,
              object elements are ordered as generated internally.
              'v':  Enables  verbose  output  of possible unsafe integers.  If
              specified, values which may exceed JSON  safe  integer  (53-bit)
              range  are  always  output  as  a number (with some 'KEY') and a
              string ('KEY_s'), regardless of the actual value.  Values  which
              may  exceed 64-bit range are also output as a little endian byte
              array ('KEY_le').  By default, the additional elements are  only
              output if the value actually exceeds the range.

              The  following two arguments are primarily indented for develop-
              ment:
              'i': Includes lines from the plaintext output which  print  info
              already  implemented  for  JSON output.  The lines appear as ob-
              jects with key 'smartctl_NNNN_i'.
              'u': Includes lines from the plaintext output which  print  info
              still  unimplemented  for  JSON output.  The lines appear as ob-
              jects with key 'smartctl_NNNN_u'.

       -q TYPE, --quietmode=TYPE
              Specifies that smartctl should run in one of the quiet modes de-
              scribed here.  The valid arguments to this option are:

              errorsonly  - only print: For the '-l error' option, if nonzero,
              the number of errors recorded in the SMART  error  log  and  the
              power-on  time when they occurred; For the '-l selftest' option,
              errors recorded in the device self-test log; For  the  '-H'  op-
              tion,  SMART  "disk  failing"  status or device Attributes (pre-
              failure or usage) which failed either now or in  the  past;  For
              the  '-A' option, device Attributes (pre-failure or usage) which
              failed either now or in the past.

              silent - print no output.  The only way to learn about what  was
              found is to use the exit status of smartctl (see EXIT STATUS be-
              low).

              noserial - Do not print the serial number of the device.

       -d TYPE, --device=TYPE
              Specifies the type of the device.  The valid arguments  to  this
              option are:

              auto  - attempt to guess the device type from the device name or
              from controller type info provided by the  operating  system  or
              from a matching USB ID entry in the drive database.  This is the
              default.

              test - prints the guessed TYPE, then opens the device and prints
              the (possibly changed) TYPE name and then exits without perform-
              ing any further commands.

              ata - the device type is ATA.  This prevents smartctl from issu-
              ing SCSI commands to an ATA device.

              scsi - the device type is SCSI.  This prevents smartctl from is-
              suing ATA commands to a SCSI device.

              nvme[,NSID] - the device type is NVM Express  (NVMe).   The  op-
              tional parameter NSID specifies the namespace id (in hex) passed
              to the driver.  Use 0xffffffff for the broadcast  namespace  id.
              The default for NSID is the namespace id addressed by the device
              name.

              sat[,auto][,N] - the device type  is  SCSI  to  ATA  Translation
              (SAT).   This  is for ATA disks that have a SCSI to ATA Transla-
              tion Layer (SATL) between the disk  and  the  operating  system.
              SAT  defines  two  ATA  PASS THROUGH SCSI commands, one 12 bytes
              long and the other 16 bytes long.  The default is  the  16  byte
              variant  which  can be overridden with either '-d sat,12' or '-d
              sat,16'.

              If '-d sat,auto' is specified, device  type  SAT  (for  ATA/SATA
              disks)  is  only  used  if  the SCSI INQUIRY data reports a SATL
              (VENDOR: "ATA     ").  Otherwise device type SCSI (for  SCSI/SAS
              disks) is used.

              usbcypress - this device type is for ATA disks that are behind a
              Cypress USB to PATA bridge.  This will use the ATACB proprietary
              scsi  pass  through command.  The default SCSI operation code is
              0x24,  but  although  it  can  be  overridden  with  '-d  usbcy-
              press,0xN',  where  N is the scsi operation code, you're running
              the risk of damage to the device or filesystems on it.

              usbjmicron[,p][,x][,PORT] - this device type is for  SATA  disks
              that  are  behind a JMicron USB to PATA/SATA bridge.  The 48-bit
              ATA commands (required e.g. for '-l xerror', see below)  do  not
              work with all of these bridges and are therefore disabled by de-
              fault.  These commands can be enabled by '-d usbjmicron,x'.   If
              two  disks  are  connected  to a bridge with two ports, an error
              message is printed if no PORT is specified.   The  port  can  be
              specified  by  '-d usbjmicron[,x],PORT' where PORT is 0 (master)
              or 1 (slave).  This is not necessary if the device uses  a  port
              multiplier to connect multiple disks to one port.  The disks ap-
              pear under separate /dev/ice names  then.   CAUTION:  Specifying
              ',x'  for  a device which does not support it results in I/O er-
              rors and may disconnect the drive.   The  same  applies  if  the
              specified PORT does not exist or is not connected to a disk.

              The Prolific PL2507/3507 USB bridges with older firmware support
              a pass-through command similar to JMicron and work with '-d usb-
              jmicron,0'.  Newer Prolific firmware requires a modified command
              which can be selected by '-d usbjmicron,p'.  Note that this does
              not yet support the SMART status command.

              usbprolific - this device type is for SATA disks that are behind
              a Prolific PL2571/2771/2773/2775 USB to SATA bridge.

              usbsunplus - this device type is for SATA disks that are  behind
              a SunplusIT USB to SATA bridge.

              sntjmicron[,NSID] - [NEW EXPERIMENTAL SMARTCTL FEATURE] this de-
              vice type is for NVMe disks that are behind  a  JMicron  USB  to
              NVMe  bridge.   The  optional parameter NSID specifies the name-
              space id (in hex) passed to the driver.  The  default  namespace
              id is the broadcast namespace id (0xffffffff).

              marvell  -  [Linux only] interact with SATA disks behind Marvell
              chip-set controllers  (using  the  Marvell  rather  than  libata
              driver).

              megaraid,N  -  [Linux  only]  the device consists of one or more
              SCSI/SAS disks connected to a MegaRAID controller.  The non-neg-
              ative  integer  N  (in  the range of 0 to 127 inclusive) denotes
              which disk on the controller is monitored.  Use syntax such as:
              smartctl -a -d megaraid,2 /dev/sda
              smartctl -a -d megaraid,0 /dev/sdb
              smartctl -a -d megaraid,0 /dev/bus/0
              This interface will also work for Dell PERC controllers.  It  is
              possible  to  set  RAID  device name as /dev/bus/N, where N is a
              SCSI bus number.

              The following entry in /proc/devices must exist:
              For PERC2/3/4 controllers: megadevN
              For PERC5/6 controllers: megaraid_sas_ioctlN

              aacraid,H,L,ID - [Linux, Windows and  Cygwin  only]  the  device
              consists  of  one or more SCSI/SAS or SATA disks connected to an
              AacRaid controller.  The non-negative integers H,L,ID (Host num-
              ber,  Lun, ID) denote which disk on the controller is monitored.
              Use syntax such as:
              smartctl -a -d aacraid,0,0,2 /dev/sda
              smartctl -a -d aacraid,1,0,4 /dev/sdb

              Option '-d sat,auto+...' is implicitly enabled  to  detect  SATA
              disks.  Use '-d scsi+aacraid,H,L,ID' to disable it.

              On  Linux, the following entry in /proc/devices must exist: aac.
              Character device nodes /dev/aacH (H=Host number) are created  if
              required.

              3ware,N - [FreeBSD and Linux only] the device consists of one or
              more ATA disks connected to a 3ware RAID controller.   The  non-
              negative  integer  N  (in the range from 0 to 127 inclusive) de-
              notes which disk on the controller  is  monitored.   Use  syntax
              such as:
              smartctl -a -d 3ware,2 /dev/sda  [Linux only]
              smartctl -a -d 3ware,0 /dev/twe0
              smartctl -a -d 3ware,1 /dev/twa0
              smartctl -a -d 3ware,1 /dev/twl0 [Linux only]
              smartctl -a -d 3ware,1 /dev/tws0 [FreeBSD only]
              The  first  two forms, which refer to devices /dev/sda-z (depre-
              cated) and /dev/twe0-15, may be used  with  3ware  series  6000,
              7000,  and  8000 series controllers that use the 3x-xxxx driver.
              The devices /dev/twa0-15, must be used with  3ware  9000  series
              controllers,   which   use  the  3w-9xxx  driver.   The  devices
              /dev/twl0-15 [Linux] or /dev/tws0-15 [FreeBSD] must be used with
              the  3ware/LSI  9750  series  controllers  which  use the 3w-sas
              driver.

              Note that if the special character  device  nodes  /dev/tw[ls]?,
              /dev/twa?   and /dev/twe? do not exist, or exist with the incor-
              rect major or minor numbers, smartctl will recreate them on  the
              fly.

              areca,N  -  [FreeBSD, Linux, Windows and Cygwin only] the device
              consists of one or more SATA disks connected to  an  Areca  SATA
              RAID controller.  The positive integer N (in the range from 1 to
              24 inclusive) denotes which disk on the controller is monitored.
              On Linux use syntax such as:
              smartctl -a -d areca,2 /dev/sg2
              smartctl -a -d areca,3 /dev/sg3
              The  first  line  above  addresses  the second disk on the first
              Areca RAID controller.  The second line addresses the third disk
              on  the second Areca RAID controller.  To help identify the cor-
              rect device on Linux, use the command:
              cat /proc/scsi/sg/device_hdr /proc/scsi/sg/devices
              to show the SCSI generic devices (one per  line,  starting  with
              /dev/sg0).   The  correct  SCSI  generic  devices to address for
              smartmontools are the ones with the type field equal to  3.   If
              the incorrect device is addressed, please read the warning/error
              messages carefully.  They should provide hints  about  what  de-
              vices to use.

              Important:  the Areca controller must have firmware version 1.46
              or later.  Lower-numbered firmware versions will give (harmless)
              SCSI error messages and no SMART information.

              areca,N/E - [FreeBSD, Linux, Windows and Cygwin only] the device
              consists of one or more SATA or SAS disks connected to an  Areca
              SAS RAID controller.  The integer N (range 1 to 128) denotes the
              channel (slot) and E (range 1 to 8) denotes the enclosure.   Im-
              portant:  This  requires  Areca  SAS controller firmware version
              1.51 or later.

              cciss,N - [FreeBSD and Linux only] the device consists of one or
              more  SCSI/SAS  or  SATA  disks  connected  to a cciss RAID con-
              troller.  The non-negative integer N (in the range from 0 to  15
              inclusive) denotes which disk on the controller is monitored.

              Option  '-d  sat,auto+...'  is implicitly enabled to detect SATA
              disks.  Use '-d scsi+cciss,N' to disable it.

              To look at disks behind HP Smart Array controllers,  use  syntax
              such as:
              smartctl  -a  -d  cciss,0 /dev/cciss/c0d0    (cciss driver under
              Linux)
              smartctl -a -d cciss,0 /dev/sg2    (hpsa or hpahcisr drivers un-
              der Linux)

              hpt,L/M/N  - [FreeBSD and Linux only] the device consists of one
              or more ATA disks  connected  to  a  HighPoint  RocketRAID  con-
              troller.   The  integer L is the controller id, the integer M is
              the channel number, and the integer N is the PMPort number if it
              is  available.   The  allowed values of L are from 1 to 4 inclu-
              sive, M are from 1 to 128 inclusive and N from 1 to 4 if  PMPort
              available.   And  also  these values are limited by the model of
              the HighPoint RocketRAID controller.  Use syntax such as:
              smartctl -a -d hpt,1/3 /dev/sda    (under Linux)
              smartctl -a -d hpt,1/2/3 /dev/sda    (under Linux)
              Note that the /dev/sda-z form should be the  device  node  which
              stands  for the disks derived from the HighPoint RocketRAID con-
              trollers under Linux and under FreeBSD, it is the character  de-
              vice which the driver registered (eg, /dev/hptrr, /dev/hptmv6).

              intelliprop,N[+TYPE] - the device consists of multiple ATA disks
              connected to an Intelliprop controller.  The integer  N  is  the
              port  number  from  0 to 3 of the ATA drive to be targeted.  The
              TYPE can be ata(default), sat, or a USB controller listed above.
              Note:  if  a  type of ATA does not work, try a type of sat.  Use
              syntax such as:
              smartctl -a -d intelliprop,1 /dev/sda    (under Linux)
              smartctl -a -d intelliprop,1+sat /dev/sda    (under Linux)
              WARNING: The disks are selected by write commands to the ATA De-
              vice  Vendor  Specific  Log  at address 0xc0.  Using this option
              with other devices may have undesirable side effects.

              jmb39x,N[,sLBA][,force][+TYPE] - [NEW EXPERIMENTAL SMARTCTL FEA-
              TURE]  the device consists of multiple SATA disks connected to a
              JMicron JMB39x RAID port multiplier.  The integer N is the  port
              number from 0 to 4.
              WARNING: The ATA pass-through commands are issued via READ/WRITE
              commands to LBA 33 of the RAID volume.  Using this  option  with
              other devices may overwrite this sector.
              The LBA could be selected in the range 33 (last sector of a GPT)
              to 62 (last sector of traditional boot area).
              By default, access to the device is refused if the selected sec-
              tor is not zero filled.  The 'force' flag disables this check.
              WARNING:  Orignal sector data is not written back if smartctl is
              aborted with a signal.

       -T TYPE, --tolerance=TYPE
              [ATA only] Specifies how tolerant smartctl should be of ATA  and
              SMART command failures.

              The  behavior  of  smartctl  depends upon whether the command is
              "optional" or "mandatory".  Here "mandatory" means "required  by
              the ATA Specification if the device implements the SMART command
              set" and "optional" means "not required by the ATA Specification
              even  if  the  device  implements  the  SMART command set."  The
              "mandatory" ATA and SMART commands are: (1) ATA IDENTIFY DEVICE,
              (2)  SMART  ENABLE/DISABLE  ATTRIBUTE  AUTOSAVE,  (3)  SMART EN-
              ABLE/DISABLE, and (4) SMART RETURN STATUS.

              The valid arguments to this option are:

              normal - exit on failure of any mandatory SMART command, and ig-
              nore  all  failures of optional SMART commands.  This is the de-
              fault.  Note that on some  devices,  issuing  unimplemented  op-
              tional  SMART  commands doesn't cause an error.  This can result
              in misleading smartctl messages such as "Feature  X  not  imple-
              mented", followed shortly by "Feature X: enabled".  In most such
              cases, contrary to the final message, Feature X is not enabled.

              conservative - exit on failure of any optional SMART command.

              permissive - ignore  failure(s)  of  mandatory  SMART  commands.
              This option may be given more than once.  Each additional use of
              this option will cause one more additional  failure  to  be  ig-
              nored.   Note  that  the use of this option can lead to messages
              like "Feature X not supported", followed shortly by  "Feature  X
              enable failed".  In a few such cases, contrary to the final mes-
              sage, Feature X is enabled.

              verypermissive - equivalent to giving a large number of '-T per-
              missive'  options:  ignore  failures  of any number of mandatory
              SMART commands.  Please see the note above.

       -b TYPE, --badsum=TYPE
              [ATA only] Specifies the action smartctl should take if a check-
              sum error is detected in the: (1) Device Identity Structure, (2)
              SMART Self-Test Log Structure, (3) SMART Attribute Value  Struc-
              ture,  (4) SMART Attribute Threshold Structure, or (5) ATA Error
              Log Structure.

              The valid arguments to this option are:

              warn - report the incorrect checksum but carry on  in  spite  of
              it.  This is the default.

              exit - exit smartctl.

              ignore - continue silently without issuing a warning.

       -r TYPE, --report=TYPE
              Intended  primarily  to help smartmontools developers understand
              the behavior of smartmontools on non-conforming or  poorly  con-
              forming  hardware.   This  option  reports  details  of smartctl
              transactions with the device.  The option can be  used  multiple
              times.   When  used  just once, it shows a record of the ioctl()
              transactions with the device.  When used more than once, the de-
              tail  of  these ioctl() transactions are reported in greater de-
              tail.  The valid arguments to this option are:

              ioctl - report all ioctl() transactions.

              ataioctl - report only ioctl() transactions with ATA devices.

              scsiioctl - report only ioctl() transactions with SCSI  devices.
              Invoking this once shows the SCSI commands in hex and the corre-
              sponding status.  Invoking it a second time adds a  hex  listing
              of  the first 64 bytes of data send to, or received from the de-
              vice.

              nvmeioctl - report only ioctl() transactions with NVMe devices.

              Any argument may include a positive integer to specify the level
              of  detail that should be reported.  The argument should be fol-
              lowed by a comma then the integer with no spaces.  For  example,
              ataioctl,2  The  default  level is 1, so '-r ataioctl,1' and '-r
              ataioctl' are equivalent.

              For testing purposes, the output of '-r ataioctl,2' can later be
              parsed  by  smartctl  itself if '-' is used as device path argu-
              ment.  The ATA command input parameters, sector data and  return
              values  are reconstructed from the debug report read from stdin.
              Then smartctl internally simulates an ATA device with  the  same
              behaviour.  This is does not work for SCSI devices yet.

       -n POWERMODE[,STATUS], --nocheck=POWERMODE[,STATUS]
              [ATA  only]  Specifies if smartctl should exit before performing
              any checks when the device is in a low-power mode.   It  may  be
              used  to  prevent  a  disk  from being spun-up by smartctl.  The
              power mode is ignored by default.

              Note: If this option is used it may also be necessary to specify
              the  device type with the '-d' option.  Otherwise the device may
              spin up due to commands issued during device type autodetection.

              By default, exit status 2 is returned if the device is in one of
              the  specified low-power modes.  This status is also returned if
              the device open or identification failed (see  EXIT  STATUS  be-
              low).  The optional STATUS parameter allows to override this de-
              fault.  STATUS is an integer in the range from 0 to  255  inclu-
              sive.  For example use '-n standby,0' to return success if a de-
              vice is in SLEEP or STANDBY mode.  Use '-n standby,3' to  return
              a unique exit status in this case.

              The valid arguments to this option are:

              never  -  check  the  device always, but print the power mode if
              '-i' is specified.

              sleep[,STATUS] - check the device unless it is in SLEEP mode.

              standby[,STATUS] - check the device unless it  is  in  SLEEP  or
              STANDBY mode.  In these modes most disks are not spinning, so if
              you want to prevent a disk from spinning up,  this  is  probably
              what you want.

              idle[,STATUS]  - check the device unless it is in SLEEP, STANDBY
              or IDLE mode.  In the IDLE state, most disks are still spinning,
              so this is probably not what you want.

       SMART FEATURE ENABLE/DISABLE COMMANDS:

              Note:  if multiple options are used to both enable and disable a
              feature, then both the enable and disable commands will  be  is-
              sued.   The enable command will always be issued before the cor-
              responding disable command.

       -s VALUE, --smart=VALUE
              Enables or disables SMART on device.   The  valid  arguments  to
              this option are on and off.

              [ATA] Note that the ATA commands SMART ENABLE/DISABLE OPERATIONS
              were declared obsolete in ATA ACS-4 Revision 10 (Nov 2015).

              [SCSI tape drive or changer] It is not necessary (or useful)  to
              enable SMART to see the TapeAlert messages.

       -o VALUE, --offlineauto=VALUE
              [ATA  only]  Enables  or  disables SMART automatic offline test,
              which scans the drive every four hours for disk  defects.   This
              command  can be given during normal system operation.  The valid
              arguments to this option are on and off.

              Note that the SMART automatic offline test command is listed  as
              "Obsolete"  in every version of the ATA and ATA/ATAPI Specifica-
              tions.  It was originally part of  the  SFF-8035i  Revision  2.0
              specification,  but  was  never  part  of any ATA specification.
              However it is implemented and used by  many  vendors.   You  can
              tell if automatic offline testing is supported by seeing if this
              command enables and disables it, as indicated by the 'Auto  Off-
              line  Data  Collection'  part  of  the SMART capabilities report
              (displayed with '-c').

              SMART provides three basic categories  of  testing.   The  first
              category,  called "online" testing, has no effect on the perfor-
              mance of the device.  It is turned on by the '-s on' option.

              The second category of  testing  is  called  "offline"  testing.
              This  type of test can, in principle, degrade the device perfor-
              mance.  The '-o on' option causes this  offline  testing  to  be
              carried  out, automatically, on a regular scheduled basis.  Nor-
              mally, the disk will suspend offline testing while disk accesses
              are taking place, and then automatically resume it when the disk
              would otherwise be idle, so in practice it  has  little  effect.
              Note  that a one-time offline test can also be carried out imme-
              diately upon receipt of a user command.  See  the  '-t  offline'
              option below, which causes a one-time offline test to be carried
              out immediately.

              The choice (made by the SFF-8035i and ATA specification authors)
              of  the  word testing for these first two categories is unfortu-
              nate, and often leads to confusion.  In  fact  these  first  two
              categories  of  online  and offline testing could have been more
              accurately described as online and offline data collection.

              The results of this automatic or immediate offline testing (data
              collection) are reflected in the values of the SMART Attributes.
              Thus, if problems or errors are detected, the  values  of  these
              Attributes will go below their failure thresholds; some types of
              errors may also appear in the SMART error log.  These are  visi-
              ble with the '-A' and '-l error' options respectively.

              Some  SMART  attribute  values  are updated only during off-line
              data collection activities; the rest are updated  during  normal
              operation of the device or during both normal operation and off-
              line testing.  The Attribute value table produced  by  the  '-A'
              option  indicates this in the UPDATED column.  Attributes of the
              first type are labeled "Offline" and Attributes  of  the  second
              type are labeled "Always".

              The  third  category of testing (and the only category for which
              the word 'testing' is really an appropriate  choice)  is  "self"
              testing.   This  third  type  of test is only performed (immedi-
              ately) when a command to run it is issued.  The  '-t'  and  '-X'
              options  can  be  used  to  carry out and abort such self-tests;
              please see below for further details.

              Any errors detected in the self testing will  be  shown  in  the
              SMART  self-test  log, which can be examined using the '-l self-
              test' option.

              Note: in this manual page, the word "Test" is used in connection
              with  the second category just described, e.g. for the "offline"
              testing.  The words "Self-test" are used in connection with  the
              third category.

       -S VALUE, --saveauto=VALUE
              [ATA]  Enables  or disables SMART autosave of device vendor-spe-
              cific Attributes.  The valid arguments to this option are on and
              off.   Note that this feature is preserved across disk power cy-
              cles, so you should only need to issue it once.

              The ATA standard does not specify  a  method  to  check  whether
              SMART autosave is enabled.  Unlike SCSI (below), smartctl is un-
              able to print a warning if autosave is disabled.

              Note that the ATA commands SMART  ENABLE/DISABLE  AUTOSAVE  were
              declared obsolete in ATA ACS-4 Revision 10 (Nov 2015).

              [SCSI]  For  SCSI  devices  this toggles the value of the Global
              Logging Target Save Disabled (GLTSD) bit  in  the  Control  Mode
              Page.   Some  disk  manufacturers set this bit by default.  This
              prevents error counters, power-up hours and  other  useful  data
              from  being  placed in non-volatile storage, so these values may
              be reset to zero the next time the device is  power-cycled.   If
              the  GLTSD  bit  is set then 'smartctl -a' will issue a warning.
              Use on to clear the GLTSD bit and thus enable saving counters to
              non-volatile storage.  For extreme streaming-video type applica-
              tions you might consider using off to set the GLTSD bit.

       -g NAME, --get=NAME, -s NAME[,VALUE], --set=NAME[,VALUE]
              Gets/sets non-SMART device settings.  Note that the '--set'  op-
              tion  shares  its short option '-s' with '--smart'.  Valid argu-
              ments are:

              all - Gets all values.  This is equivalent to
              '-g aam -g apm -g lookahead -g security -g wcache -g  rcache  -g
              dsn'

              aam[,N|off]  -  [ATA only] Gets/sets the Automatic Acoustic Man-
              agement (AAM) feature (if supported).  A value of 128  sets  the
              most  quiet  (slowest)  mode and 254 the fastest (loudest) mode,
              'off' disables AAM.  Devices may  support  intermediate  levels.
              Values  below  128 are defined as vendor specific (0) or retired
              (1 to 127).  Note that the AAM feature was declared obsolete  in
              ATA ACS-2 Revision 4a (Dec 2010).

              apm[,N|off] - [ATA only] Gets/sets the Advanced Power Management
              (APM) feature on device (if supported).  If a  value  between  1
              and  254  is provided, it will attempt to enable APM and set the
              specified value, 'off' disables APM.  Note the  actual  behavior
              depends  on  the  drive,  for example some drives disable APM if
              their value is set above 128.  Values below 128 are supposed  to
              allow  drive  spindown,  values  128 and above adjust only head-
              parking frequency, although the actual behavior defined is  also
              vendor-specific.

              lookahead[,on|off]  -  [ATA  only] Gets/sets the read look-ahead
              feature (if supported).  Read look-ahead is usually  enabled  by
              default.

              security  -  [ATA  only] Gets the status of ATA Security feature
              (if supported).  If ATA Security is enabled an ATA user password
              is set.  The drive will be locked on next reset then.

              security-freeze - [ATA only] Sets ATA Security feature to frozen
              mode.  This prevents that the drive accepts  any  security  com-
              mands  until  next reset.  Note that the frozen mode may already
              be set by BIOS or OS.

              standby,[N|off] - [ATA only] Sets the standby  (spindown)  timer
              and  places  the  drive in the IDLE mode.  A value of 0 or 'off'
              disables the standby timer.  Values from 1 to 240 specify  time-
              outs  from 5 seconds to 20 minutes in 5 second increments.  Val-
              ues from 241 to 251 specify timeouts from 30 minutes to 330 min-
              utes  in  30 minute increments.  Value 252 specifies 21 minutes.
              Value 253 specifies a vendor specific  time  between  8  and  12
              hours.   Value  255  specifies  21 minutes and 15 seconds.  Some
              drives may use a vendor specific interpretation for the  values.
              Note  that  there  is no get option because ATA standards do not
              specify a method to read the standby timer.  If '-s standby,now'
              is  also  specified,  the  drive  is  immediately  placed in the
              STANDBY mode without temporarily placing it in  the  IDLE  mode.
              Note  that  ATA  standards  do  not specify a command to set the
              standby timer without affecting the power mode.

              standby,now - [ATA only] Places the drive in the  STANDBY  mode.
              This  usually  spins down the drive.  The setting of the standby
              timer is not affected unless '-s standby,[N|off]' is also speci-
              fied.

              wcache[,on|off]  - [ATA] Gets/sets the volatile write cache fea-
              ture (if supported).  The write cache is usually enabled by  de-
              fault.

              wcache[,on|off]  -  [SCSI]  Gets/sets  the  'Write Cache Enable'
              (WCE) bit (if supported).  The write cache is usually enabled by
              default.

              wcache-sct[,ata|on|off[,p]]  -  [ATA  only]  Gets/sets the write
              cache feature through SCT Feature Control (if  supported).   The
              state of write cache in SCT Feature Control could be "Controlled
              by ATA", "Force Enabled", or "Force Disabled".  SCT Feature con-
              trol   overwrites  the  setting  by  ATA  Set  Features  command
              (wcache[,on|off] option).  If SCT  Feature  Control  sets  write
              cache  as  "Force  Enabled"  or "Force Disabled", the setting of
              wcache[,on|off] is ignored by the drive.   SCT  Feature  Control
              usually  sets write cache as "Controlled by ATA" by default.  If
              ',p' is specified, the setting is preserved across power cycles.

              wcreorder[,on|off[,p]] - [ATA only] Gets/sets  Write  Cache  Re-
              ordering.  If it is disabled (off), disk write scheduling is ex-
              ecuted on a first-in-first-out (FIFO) basis.  If Write Cache Re-
              ordering  is enabled (on), then disk write scheduling may be re-
              ordered by the drive.  If write cache is disabled,  the  current
              Write  Cache Reordering state is remembered but has no effect on
              non-cached writes, which are always written  in  the  order  re-
              ceived.   The  state  of Write Cache Reordering has no effect on
              either NCQ or LCQ queued commands.  If ',p'  is  specified,  the
              setting is preserved across power cycles.

              rcache[,on|off] - [SCSI only] Gets/sets the 'Read Cache Disable'
              (RCE) bit.  'Off' value disables read cache (if supported).  The
              read cache is usually enabled by default.

              dsn[,on|off]  -  [ATA  only]  Gets/sets the DSN feature (if sup-
              ported).  The dsn is usually disabled by default.

       SMART READ AND DISPLAY DATA OPTIONS:

       -H, --health
              Prints the health status of the device or pending TapeAlert mes-
              sages.

              If  the  device reports failing health status, this means either
              that the device has already failed, or that it is predicting its
              own  failure within the next 24 hours.  If this happens, use the
              '-a' option to get more information, and get your data  off  the
              disk and to someplace safe as soon as you can.

              [ATA] Health status is obtained by checking the (boolean) result
              returned by the SMART RETURN STATUS command.  The  return  value
              of this ATA command may be unknown due to limitations or bugs in
              some layer (e.g. RAID controller or USB bridge firmware) between
              disk  and  operating  system.   In  this case, smartctl prints a
              warning and checks whether any Prefailure SMART Attribute  value
              is less than or equal to its threshold (see '-A' below).

              [SCSI]  Health  status  is  obtained  by checking the Additional
              Sense Code (ASC) and Additional Sense Code Qualifier (ASCQ) from
              Informal  Exceptions  (IE)  log  page (if supported) and/or from
              SCSI sense data.

              [SCSI tape drive or changer] TapeAlert  status  is  obtained  by
              reading  the TapeAlert log page.  Please note that the TapeAlert
              log page flags are cleared for the initiator when  the  page  is
              read.   This  means  that  each alert condition is reported only
              once by smartctl for each initiator for each activation  of  the
              condition.

              [NVMe] NVMe status is obtained by reading the "Critical Warning"
              byte from the SMART/Health Information log.

       -c, --capabilities
              [ATA] Prints only the generic SMART  capabilities.   These  show
              what  SMART features are implemented and how the device will re-
              spond to some of the different SMART commands.  For  example  it
              shows  if the device logs errors, if it supports offline surface
              scanning, and so on.  If the device can  carry  out  self-tests,
              this  option also shows the estimated time required to run those
              tests.

              [NVMe] Prints various NVMe device capabilities obtained from the
              Identify Controller and the Identify Namespace data structure.

       -A, --attributes
              [ATA] Prints only the vendor specific SMART Attributes.  The At-
              tributes are numbered from 1 to 253 and have specific names  and
              ID  numbers.   For  example Attribute 12 is "power cycle count":
              how many times has the disk been powered up.

              Each Attribute has a "Raw"  value,  printed  under  the  heading
              "RAW_VALUE",  and a "Normalized" value printed under the heading
              "VALUE".  [Note: smartctl prints these values in  base-10.]   In
              the  example  just given, the "Raw Value" for Attribute 12 would
              be the actual number of times that the disk has  been  power-cy-
              cled,  for  example  365 if the disk has been turned on once per
              day for exactly one year.  Each vendor uses their own  algorithm
              to convert this "Raw" value to a "Normalized" value in the range
              from 1 to 254.  Please keep in mind that smartctl  only  reports
              the  different  Attribute  types, values, and thresholds as read
              from the device.  It does not carry out the  conversion  between
              "Raw"  and  "Normalized"  values:  this  is  done  by the disk's
              firmware.

              The conversion from Raw value to a quantity with physical  units
              is not specified by the SMART standard.  In most cases, the val-
              ues printed by smartctl are sensible.  For example the  tempera-
              ture Attribute generally has its raw value equal to the tempera-
              ture in Celsius.  However in some cases vendors use unusual con-
              ventions.  For example the Hitachi disk on my laptop reports its
              power-on hours in minutes, not  hours.   Some  IBM  disks  track
              three temperatures rather than one, in their raw values.  And so
              on.

              Each Attribute also has a Threshold value (whose range is  0  to
              255)  which  is printed under the heading "THRESH".  If the Nor-
              malized value is less than or equal to the Threshold value, then
              the  Attribute  is  said  to have failed.  If the Attribute is a
              pre-failure Attribute, then disk failure is imminent.

              Each Attribute also has a "Worst" value shown under the  heading
              "WORST".   This  is the smallest (closest to failure) value that
              the disk has recorded at any time during its lifetime when SMART
              was enabled.  [Note however that some vendors firmware may actu-
              ally  increase  the  "Worst"  value  for  some  "rate-type"  At-
              tributes.]

              The  Attribute  table  printed  out  by  smartctl also shows the
              "TYPE" of the Attribute.  Attributes are  one  of  two  possible
              types:  Pre-failure or Old age.  Pre-failure Attributes are ones
              which, if less than or equal to their threshold values, indicate
              pending  disk  failure.   Old age, or usage Attributes, are ones
              which indicate end-of-product life from old-age or normal  aging
              and wearout, if the Attribute value is less than or equal to the
              threshold.  Please note: the fact that an Attribute is  of  type
              'Pre-fail'  does  not  mean that your disk is about to fail!  It
              only has this meaning  if  the  Attribute's  current  Normalized
              value is less than or equal to the threshold value.

              If  the  Attribute's  current  Normalized  value is less than or
              equal to the threshold value, then the "WHEN_FAILED" column will
              display  "FAILING_NOW".  If not, but the worst recorded value is
              less than or equal to the threshold value, then this column will
              display "In_the_past".  If the "WHEN_FAILED" column has no entry
              (indicated by a dash: '-') then this Attribute is  OK  now  (not
              failing) and has also never failed in the past.

              The  table column labeled "UPDATED" shows if the SMART Attribute
              values are updated during both  normal  operation  and  off-line
              testing, or only during offline testing.  The former are labeled
              "Always" and the latter are labeled "Offline".

              So to summarize: the Raw Attribute  values  are  the  ones  that
              might  have a real physical interpretation, such as "Temperature
              Celsius", "Hours", or "Start-Stop  Cycles".   Each  manufacturer
              converts these, using their detailed knowledge of the disk's op-
              erations and failure modes, to Normalized  Attribute  values  in
              the  range  1-254.   The  current and worst (lowest measured) of
              these Normalized Attribute values are stored on the disk,  along
              with a Threshold value that the manufacturer has determined will
              indicate that the disk is going to fail, or that it has exceeded
              its  design age or aging limit.  smartctl does not calculate any
              of the Attribute values, thresholds, or types, it merely reports
              them from the SMART data on the device.

              Note  that starting with ATA/ATAPI-4, revision 4, the meaning of
              these Attribute fields has been made  entirely  vendor-specific.
              However most newer ATA/SATA disks seem to respect their meaning,
              so we have retained the option of printing the Attribute values.

              Solid-state drives use different meanings for some  of  the  at-
              tributes.   In  this case the attribute name printed by smartctl
              is incorrect unless the drive is already  in  the  smartmontools
              drive database.

              Note  that the ATA command SMART READ DATA was declared obsolete
              in ATA ACS-4 Revision 10 (Nov 2015).

              [SCSI] For SCSI devices the "attributes" are obtained  from  the
              temperature  and  start-stop  cycle  counter log pages.  Certain
              vendor specific attributes are listed if  recognised.   The  at-
              tributes  are  output in a relatively free format (compared with
              ATA disk attributes).

              [NVMe] For NVMe devices the attributes  are  obtained  from  the
              SMART/Health Information log.

       -f FORMAT, --format=FORMAT
              [ATA only] Selects the output format of the attributes:

              old  - Old smartctl format.  This is the default unless the '-x'
              option is specified.

              brief - New format which fits into 80 columns  (except  in  some
              rare cases).  This format also decodes four additional attribute
              flags.  This is the default if the '-x' option is specified.

              hex,id - Print all attribute IDs as hexadecimal numbers.

              hex,val - Print all normalized values as hexadecimal numbers.

              hex - Same as '-f hex,id -f hex,val'.

       -l TYPE, --log=TYPE
              Prints various device logs.  The valid arguments to this  option
              are:

              error  -  [ATA] prints the Summary SMART error log.  SMART disks
              maintain a log of the most recent five non-trivial errors.   For
              each  of  these  errors, the disk power-on lifetime at which the
              error occurred is recorded,  as  is  the  device  status  (idle,
              standby,  etc)  at the time of the error.  For some common types
              of errors, the Error Register (ER) and Status Register (SR) val-
              ues are decoded and printed as text.  The meanings of these are:
                 ABRT:  Command ABoRTed
                 AMNF:  Address Mark Not Found
                 CCTO:  Command Completion Timed Out
                 EOM:   End Of Media
                 ICRC:  Interface Cyclic Redundancy Code (CRC) error
                 IDNF:  IDentity Not Found
                 ILI:   (packet command-set specific)
                 MC:    Media Changed
                 MCR:   Media Change Request
                 NM:    No Media
                 obs:   obsolete
                 TK0NF: TracK 0 Not Found
                 UNC:   UNCorrectable Error in Data
                 WP:    Media is Write Protected
              In  addition, up to the last five commands that preceded the er-
              ror are listed, along with a timestamp measured from  the  start
              of the corresponding power cycle.  This is displayed in the form
              Dd+HH:MM:SS.msec where D is the number of days, HH is hours,  MM
              is minutes, SS is seconds and msec is milliseconds.  [Note: this
              time stamp wraps after 2^32 milliseconds, or 49 days 17 hours  2
              minutes  and  47.296  seconds.]   The key ATA disk registers are
              also recorded in the log.  The final column of the error log  is
              a text-string description of the ATA command defined by the Com-
              mand Register (CR) and Feature Register (FR)  values.   Commands
              that are obsolete in the most current spec are listed like this:
              READ LONG (w/ retry) [OBS-4], indicating that the command became
              obsolete with or in the ATA-4 specification.  Similarly, the no-
              tation [RET-N] is used to indicate that a command was retired in
              the  ATA-N  specification.  Some commands are not defined in any
              version of the ATA specification but are in common use  nonethe-
              less; these are marked [NS], meaning non-standard.

              The  ATA  Specification  (ATA  ACS-2  Revision 7, Section A.7.1)
              says: "Error log data structures shall include, but are not lim-
              ited to, Uncorrectable errors, ID Not Found errors for which the
              LBA requested was valid, servo errors, and write  fault  errors.
              Error log data structures shall not include errors attributed to
              the receipt of faulty commands."  The definitions of these terms
              are:
              UNC (UNCorrectable): data is uncorrectable.  This refers to data
              which has been read from the  disk,  but  for  which  the  Error
              Checking  and  Correction  (ECC) codes are inconsistent.  In ef-
              fect, this means that the data can not be read.
              IDNF (ID Not Found): user-accessible address could not be found.
              For READ LOG type commands, IDNF can also indicate that a device
              data log structure checksum was incorrect.

              If the command that caused the error was a READ  or  WRITE  com-
              mand,  then  the  Logical Block Address (LBA) at which the error
              occurred will be printed in base 10 and base 16.  The LBA  is  a
              linear  address,  which  counts  512-byte  sectors  on the disk,
              starting from zero.  (Because of the limitations  of  the  SMART
              error  log, if the LBA is greater than 0xfffffff, then either no
              error log entry will be made, or the error log entry  will  have
              an  incorrect  LBA.   This may happen for drives with a capacity
              greater than 128 GiB or 137 GB.)  On Linux systems the smartmon-
              tools web page has instructions about how to convert the LBA ad-
              dress to the name of the disk file containing the erroneous disk
              sector.

              Please  note  that  some manufacturers ignore the ATA specifica-
              tions, and make entries in the error log if the device  receives
              a command which is not implemented or is not valid.

              error  -  [SCSI]  prints  the error counter log pages for reads,
              write and verifies.  The verify row is only output if it has  an
              element other than zero.

              error[,NUM]  -  [NVMe]  prints  the  NVMe Error Information log.
              Only the 16 most recent log  entries  are  printed  by  default.
              This  number  can be changed by the optional parameter NUM.  The
              maximum number of log entries is vendor specific (in  the  range
              from 1 to 256 inclusive).

              xerror[,NUM][,error] - [ATA only] prints the Extended Comprehen-
              sive SMART error log (General Purpose Log address 0x03).  Unlike
              the  Summary SMART error log (see '-l error' above), it provides
              sufficient space to log the contents of the 48-bit LBA  register
              set introduced with ATA-6.  It also supports logs with more than
              one sector.  Each sector holds up to 4 log entries.  The  actual
              number of log sectors is vendor specific.

              Only the 8 most recent error log entries are printed by default.
              This number can be changed by the optional parameter NUM.

              If ',error' is appended and the Extended Comprehensive SMART er-
              ror  log  is  not  supported, the Summary SMART self-test log is
              printed.

              Please note that recent drives may report errors only in the Ex-
              tended  Comprehensive  SMART error log.  The Summary SMART error
              log may be reported as supported but is always empty then.

              selftest - [ATA] prints the SMART self-test log.  The disk main-
              tains  a  self-test  log  showing the results of the self tests,
              which can be run using the '-t'  option  described  below.   For
              each of the most recent twenty-one self-tests, the log shows the
              type of test (short or extended, off-line or  captive)  and  the
              final status of the test.  If the test did not complete success-
              fully, then the percentage of the test remaining is shown.   The
              time  at  which  the  test took place, measured in hours of disk
              lifetime, is also printed.  [Note: this time stamp  wraps  after
              2^16  hours, or 2730 days and 16 hours, or about 7.5 years.]  If
              any errors were detected, the Logical Block Address (LBA) of the
              first error is printed in decimal notation.

              selftest  -  [SCSI]  the  self-test  log for a SCSI device has a
              slightly different format than for an ATA device.  For  each  of
              the most recent twenty self-tests, it shows the type of test and
              the status (final or in progress) of the test.   SCSI  standards
              use  the  terms "foreground" and "background" (rather than ATA's
              corresponding "captive" and "off-line") and "short"  and  "long"
              (rather  than ATA's corresponding "short" and "extended") to de-
              scribe the type of the test.  The printed segment number is only
              relevant  when  a test fails in the third or later test segment.
              It identifies the test that failed and consists  of  either  the
              number of the segment that failed during the test, or the number
              of the test that failed and the number of the segment  in  which
              the test was run, using a vendor-specific method of putting both
              numbers into a single byte.  The Logical Block Address (LBA)  of
              the  first  error  is  printed in hexadecimal notation.  If pro-
              vided, the SCSI Sense Key (SK), Additional Sense Code (ASC)  and
              Additional  Sense  Code  Qualifier (ASCQ) are also printed.  The
              self tests can be run using the '-t' option described below (us-
              ing the ATA test terminology).

              xselftest[,NUM][,selftest]  -  [ATA  only]  prints  the Extended
              SMART self-test log (General Purpose Log address 0x07).   Unlike
              the  SMART  self-test log (see '-l selftest' above), it supports
              48-bit LBA and logs with more  than  one  sector.   Each  sector
              holds up to 19 log entries.  The actual number of log sectors is
              vendor specific.

              Only the 25 most recent log  entries  are  printed  by  default.
              This number can be changed by the optional parameter NUM.

              If  ',selftest' is appended and the Extended SMART self-test log
              is not supported, the old SMART self-test log is printed.

              selective - [ATA only] Please see the '-t select'  option  below
              for  a description of selective self-tests.  The selective self-
              test log shows the start/end Logical Block  Addresses  (LBA)  of
              each  of the five test spans, and their current test status.  If
              the span is being tested or the remainder of the disk  is  being
              read-scanned,  the  current  65536-sector  block  of  LBAs being
              tested is also displayed.   The  selective  self-test  log  also
              shows  if  a read-scan of the remainder of the disk will be car-
              ried out after the selective self-test has  completed  (see  '-t
              afterselect'  option)  and the time delay before restarting this
              read-scan if it is interrupted (see '-t pending' option).

              directory[,gs] - [ATA only] if the device supports  the  General
              Purpose  Logging  feature set (ATA-6 and above) then this prints
              the Log Directory (the log at address  0).   The  Log  Directory
              shows  what  logs are available and their length in sectors (512
              bytes).  The contents of the logs at address  1  [Summary  SMART
              error log] and at address 6 [SMART self-test log] may be printed
              using the previously-described error and selftest  arguments  to
              this  option.   If  your version of smartctl supports 48-bit ATA
              commands, both the General Purpose Log (GPL) and SMART Log  (SL)
              directories  are  printed in one combined table.  The output can
              be restricted to the GPL directory or SL directory by '-l direc-
              tory,q' or '-l directory,s' respectively.

              background - [SCSI only] the background scan results log outputs
              information derived from Background Media Scans (BMS) done after
              power  up  and/or  periodically  (e.g. every 24 hours) on recent
              SCSI disks.  If supported, the BMS status is output first, indi-
              cating  whether  a background scan is currently underway (and if
              so a progress percentage), the amount of time the disk has  been
              powered  up  and  the  number  of scans already completed.  Then
              there is a header and a line for each background  scan  "event".
              These  will  typically  be either recovered or unrecoverable er-
              rors.  That latter group may need some attention.   There  is  a
              description  of the background scan mechanism in section 4.18 of
              SBC-3 revision 6 (see www.t10.org ).

              scttemp, scttempsts, scttemphist - [ATA only]  prints  the  disk
              temperature  information provided by the SMART Command Transport
              (SCT) commands.  The option 'scttempsts' prints current tempera-
              ture  and temperature ranges returned by the SCT Status command,
              'scttemphist' prints temperature limits and the temperature his-
              tory table returned by the SCT Data Table command, and 'scttemp'
              prints both.  The temperature values are preserved across  power
              cycles.   The  logging  interval  can be configured with the '-l
              scttempint,N[,p]' option, see below.  The SCT commands were  in-
              troduced  in  ATA8-ACS  and  were  also  supported by many ATA-7
              disks.

              scttempint,N[,p] - [ATA only] clears the SCT temperature history
              table  and  sets  the time interval for temperature logging to N
              minutes.  If ',p' is specified, the setting is preserved  across
              power  cycles.   Otherwise,  the setting is volatile and will be
              reverted to the last non-volatile setting by the next  hard  re-
              set.   The  default  interval is vendor specific, typical values
              are 1, 2, or 5 minutes.

              scterc[,READTIME,WRITETIME] - [ATA only] prints values  and  de-
              scriptions  of  the  SCT Error Recovery Control settings.  These
              are equivalent to TLER (as used by Western  Digital),  CCTL  (as
              used  by Samsung and Hitachi/HGST) and ERC (as used by Seagate).
              READTIME and WRITETIME arguments (deciseconds) set the specified
              values.  Values of 0 disable the feature, other values less than
              65 are probably not supported.  For RAID configurations, this is
              typically set to 70,70 deciseconds.

              devstat[,PAGE]  -  [ATA  only] prints values and descriptions of
              the ATA Device Statistics log pages (General Purpose Log address
              0x04).   If  no  PAGE number is specified, entries from all sup-
              ported pages are printed.  If PAGE 0 is specified, the  list  of
              supported pages is printed.  Device Statistics was introduced in
              ACS-2 and is only supported by some recent devices.

              defects[,NUM] - [ATA only] prints LBA and hours values from  the
              ATA  Pending  Defects  log  (General  Purpose Log address 0x0c).
              Only the 31 entries from first log page are printed by  default.
              This  number  can be changed by the optional parameter NUM.  The
              size of the log and the order of the  entries  are  vendor  spe-
              cific.  The Pending Defects log was introduced in ACS-4 Revision
              01 (Mar 2014).

              sataphy[,reset] - [SATA only] prints values and descriptions  of
              the  SATA Phy Event Counters (General Purpose Log address 0x11).
              If '-l sataphy,reset' is specified, all counters are reset after
              reading  the  values.   This  also  works  for SATA devices with
              Packet interface like CD/DVD drives.

              sasphy[,reset] - [SAS (SCSI) only] prints  values  and  descrip-
              tions  of  the  SAS  (SSP)  Protocol Specific log page (log page
              0x18).  If '-l sasphy,reset' is specified, all counters are  re-
              set after reading the values.

              gplog,ADDR[,FIRST[-LAST|+SIZE]]  -  [ATA only] prints a hex dump
              of any log accessible via General Purpose Logging (GPL) feature.
              The log address ADDR is the hex address listed in the log direc-
              tory (see '-l directory'  above).   The  range  of  log  sectors
              (pages)  can  be  specified  by  decimal  values  FIRST-LAST  or
              FIRST+SIZE.  FIRST defaults to 0, SIZE defaults to 1.  LAST  can
              be set to 'max' to specify the last page of the log.

              smartlog,ADDR[,FIRST[-LAST|+SIZE]]  -  [ATA  only]  prints a hex
              dump of any log accessible via SMART Read Log command.  See  '-l
              gplog,...' above for parameter syntax.

              For example, all these commands:
                smartctl -l gplog,0x80,10-15 /dev/sda
                smartctl -l gplog,0x80,10+6 /dev/sda
                smartctl -l smartlog,0x80,10-15 /dev/sda
              print pages 10-15 of log 0x80 (first host vendor specific log).

              The  hex  dump  format  is compatible with the 'xxd -r' command.
              This command:
                smartctl -l gplog,0x11 /dev/sda | grep ^0 | xxd -r >log.bin
              writes a binary representation of the one sector log 0x11  (SATA
              Phy Event Counters) to file log.bin.

              nvmelog,PAGE,SIZE  -  [NVMe only] prints a hex dump of the first
              SIZE bytes from the NVMe log with identifier PAGE.   PAGE  is  a
              hexadecimal  number  in  the  range from 0x1 to 0xff.  SIZE is a
              hexadecimal number in the range from 0x4  to  0x4000  (16  KiB).
              WARNING:  Do  not specify the identifier of an unknown log page.
              Reading a log page may have undesirable side effects.

              ssd - [ATA] prints the Solid State Device Statistics  log  page.
              This has the same effect as '-l devstat,7', see above.

              ssd  -  [SCSI]  prints the Solid State Media percentage used en-
              durance indicator.  A value of  0  indicates  as  new  condition
              while  100 indicates the device is at the end of its lifetime as
              projected by the manufacturer.  The value may reach 255.

       -v ID,FORMAT[:BYTEORDER][,NAME], --vendorattribute=ID,FORMAT...
              [ATA only] Sets a vendor-specific raw value print FORMAT, an op-
              tional  BYTEORDER  and  an optional NAME for Attribute ID.  This
              option may be used multiple times.

              The Attribute ID can be in the range 1 to 255.  If 'N' is speci-
              fied as ID, the settings for all Attributes are changed.

              The  optional  BYTEORDER  consists of 1 to 8 characters from the
              set '012345rvwz'.  The characters '0' to '5' select the  byte  0
              to 5 from the 48-bit raw value, 'r' selects the reserved byte of
              the attribute data block, 'v' selects the normalized value,  'w'
              selects  the  worst  value and 'z' inserts a zero byte.  The de-
              fault BYTEORDER is '543210' for all  48-bit  formats,  'r543210'
              for  the  54-bit formats, and '543210wv' for the 64-bit formats.
              For example, '-v 5,raw48:012345' prints the raw value of  attri-
              bute 5 with big endian instead of little endian byte ordering.

              The  NAME  is  a  string of letters, digits and underscore.  Its
              length should not exceed 23 characters.  The '-P showall' option
              reports an error if this is the case.

              -v  help  -  Prints (to STDOUT) a list of all valid arguments to
              this option, then exits.

              Valid arguments for FORMAT are:

              raw8 - Print the Raw value as six 8-bit unsigned  base-10  inte-
              gers.   This  may  be useful for decoding the meaning of the Raw
              value.

              raw16 - Print the Raw value as three 16-bit unsigned base-10 in-
              tegers.   This may be useful for decoding the meaning of the Raw
              value.

              raw48 - Print the Raw value as a 48-bit unsigned  base-10  inte-
              ger.  This is the default for most attributes.

              hex48  -  Print  the Raw value as a 12 digit hexadecimal number.
              This may be useful for decoding the meaning of the Raw value.

              raw56 - Print the Raw value as a 54-bit unsigned  base-10  inte-
              ger.   This  includes the reserved byte which follows the 48-bit
              raw value.

              hex56 - Print the Raw value as a 14  digit  hexadecimal  number.
              This  includes  the  reserved  byte which follows the 48-bit raw
              value.

              raw64 - Print the Raw value as a 64-bit unsigned  base-10  inte-
              ger.   This includes two bytes from the normalized and worst at-
              tribute value.  This raw format is used by some SSD devices with
              Indilinx controller.

              hex64  -  Print  the Raw value as a 16 digit hexadecimal number.
              This includes two bytes from the normalized and worst  attribute
              value.   This raw format is used by some SSD devices with Indil-
              inx controller.

              min2hour - Raw Attribute is power-on time in minutes.   Its  raw
              value  will  be displayed in the form "Xh+Ym".  Here X is hours,
              and Y is minutes in the  range  0-59  inclusive.   Y  is  always
              printed with two digits, for example "06" or "31" or "00".

              sec2hour  -  Raw Attribute is power-on time in seconds.  Its raw
              value will be displayed in  the  form  "Xh+Ym+Zs".   Here  X  is
              hours,  Y  is minutes in the range 0-59 inclusive, and Z is sec-
              onds in the range 0-59 inclusive.  Y and Z  are  always  printed
              with two digits, for example "06" or "31" or "00".

              halfmin2hour - Raw Attribute is power-on time, measured in units
              of 30 seconds.  This format is used by some Samsung disks.   Its
              raw  value  will  be  displayed  in the form "Xh+Ym".  Here X is
              hours, and Y is minutes in the range 0-59 inclusive.  Y  is  al-
              ways printed with two digits, for example "06" or "31" or "00".

              msec24hour32 - Raw Attribute is power-on time measured in 32-bit
              hours and 24-bit milliseconds since last hour update.   It  will
              be  displayed  in  the form "Xh+Ym+Z.Ms".  Here X is hours, Y is
              minutes, Z is seconds and M is milliseconds.

              tempminmax - Raw Attribute is the disk temperature  in  Celsius.
              Info about Min/Max temperature is printed if available.  This is
              the default for Attributes 190 and 194.  The recording  interval
              (lifetime,  last  power  cycle,  last soft reset) of the min/max
              values is device specific.

              temp10x - Raw Attribute is ten times  the  disk  temperature  in
              Celsius.

              raw16(raw16) - Print the raw attribute as a 16-bit value and two
              optional 16-bit values if these words are nonzero.  This is  the
              default for Attributes 5 and 196.

              raw16(avg16)  - Raw attribute is spin-up time.  It is printed as
              a 16-bit value and an optional "Average"  16-bit  value  if  the
              word is nonzero.  This is the default for Attribute 3.

              raw24(raw8)  -  Print  the  raw  attribute as a 24-bit value and
              three optional 8-bit values if these bytes are nonzero.  This is
              the default for Attribute 9.

              raw24/raw24  -  Raw  Attribute  contains two 24-bit values.  The
              first is the number of load cycles.  The second is the number of
              unload  cycles.   The difference between these two values is the
              number of times that the  drive  was  unexpectedly  powered  off
              (also  called an emergency unload).  As a rule of thumb, the me-
              chanical stress created by one emergency unload is equivalent to
              that created by one hundred normal unloads.

              raw24/raw32 - Raw attribute is an error rate which consists of a
              24-bit error count and a 32-bit total count.

              The following old arguments to '-v' are also still valid:

              9,minutes - same as: 9,min2hour,Power_On_Minutes.

              9,seconds - same as: 9,sec2hour,Power_On_Seconds.

              9,halfminutes - same as: 9,halfmin2hour,Power_On_Half_Minutes.

              9,temp - same as: 9,tempminmax,Temperature_Celsius.

              192,emergencyretractcyclect  -  same   as:   192,raw48,Emerg_Re-
              tract_Cycle_Ct

              193,loadunload - same as: 193,raw24/raw24.

              194,10xCelsius - same as: 194,temp10x,Temperature_Celsius_x10.

              194,unknown - same as: 194,raw48,Unknown_Attribute.

              197,increasing - same as: 197,raw48,Total_Pending_Sectors.  Also
              means that Attribute number 197 (Current Pending  Sector  Count)
              is  not  reset  if  uncorrectable  sectors  are reallocated (see
              smartd.conf(5) man page).

              198,increasing  -  same  as:  198,raw48,Total_Offl_Uncorrectabl.
              Also means that Attribute number 198 (Offline Uncorrectable Sec-
              tor Count) is not reset if uncorrectable sectors are reallocated
              (see smartd.conf(5) man page).

              198,offlinescanuncsectorct    -    same    as:    198,raw48,Off-
              line_Scan_UNC_SectCt.

              200,writeerrorcount - same as: 200,raw48,Write_Error_Count.

              201,detectedtacount - same as: 201,raw48,Detected_TA_Count.

              220,temp - same as: 220,tempminmax,Temperature_Celsius.

       -F TYPE, --firmwarebug=TYPE
              [ATA only] Modifies the behavior of smartctl to  compensate  for
              some  known  and understood device firmware or driver bug.  This
              option may be used multiple times.  The valid arguments are:

              none - Assume that the device firmware obeys the ATA  specifica-
              tions.   This  is the default, unless the device has presets for
              '-F' in the drive database.  Using this option  on  the  command
              line will override any preset values.

              nologdir  -  Suppresses  read attempts of SMART or GP Log Direc-
              tory.  Support for all standard logs is assumed without  an  ac-
              tual  check.   Some  Intel  SSDs  may freeze if log address 0 is
              read.

              samsung - In some Samsung disks (example: model SV4012H Firmware
              Version:  RM100-08) some of the two- and four-byte quantities in
              the SMART data structures are byte-swapped (relative to the  ATA
              specification).  Enabling this option tells smartctl to evaluate
              these quantities in byte-reversed order.  Some signs  that  your
              disk  needs  this  option are (1) no self-test log printed, even
              though you have run self-tests; (2) very large  numbers  of  ATA
              errors reported in the ATA error log; (3) strange and impossible
              values for the ATA error log timestamps.

              samsung2 - In some Samsung disks the number of  ATA  errors  re-
              ported  is byte swapped.  Enabling this option tells smartctl to
              evaluate this quantity in byte-reversed  order.   An  indication
              that  your  Samsung disk needs this option is that the self-test
              log is printed correctly, but there are a very large  number  of
              errors  in the SMART error log.  This is because the error count
              is byte swapped.  Thus a disk with five errors (0x0005) will ap-
              pear to have 20480 errors (0x5000).

              samsung3  -  Some  Samsung disks (at least SP2514N with Firmware
              VF100-37) report a self-test still in progress with 0% remaining
              when the test was already completed.  Enabling this option modi-
              fies the output of the self-test execution status  (see  options
              '-c' or '-a' above) accordingly.

              xerrorlba  -  Fixes  LBA byte ordering in Extended Comprehensive
              SMART error log.  Some disks use little endian byte ordering in-
              stead  of  ATA register ordering to specify the LBA addresses in
              the log entries.

              swapid - Fixes byte swapped ATA identify strings  (device  name,
              serial  number,  firmware version) returned by some buggy device
              drivers.

       -P TYPE, --presets=TYPE
              [ATA only] Specifies whether smartctl should use any preset  op-
              tions  that  are  available  for this drive.  By default, if the
              drive is recognized in the smartmontools database, then the pre-
              sets are used.

              The  argument  show  will show any preset options for your drive
              and the argument showall will  show  all  known  drives  in  the
              smartmontools  database,  along  with  their preset options.  If
              there are no presets for your drive and you think  there  should
              be  (for example, a -v or -F option is needed to get smartctl to
              display correct values) then please  contact  the  smartmontools
              developers  so  that this information can be added to the smart-
              montools database.  Contact information is at the  end  of  this
              man page.

              The valid arguments to this option are:

              use  - if a drive is recognized, then use the stored presets for
              it.  This is the default.  Note that presets will  NOT  override
              additional  Attribute interpretation ('-v N,something') command-
              line options or explicit '-F' command-line options..

              ignore - do not use presets.

              show - show if the drive is recognized in the database,  and  if
              so, its presets, then exit.

              showall  -  list all recognized drives, and the presets that are
              set for them, then exit.  This also checks  the  drive  database
              regular expressions and settings for syntax errors.

              The  '-P  showall'  option takes up to two optional arguments to
              match a specific drive type and firmware version.  The command:
                smartctl -P showall
              lists all entries, the command:
                smartctl -P showall 'MODEL'
              lists all entries matching MODEL, and the command:
                smartctl -P showall 'MODEL' 'FIRMWARE'
              lists all entries for this MODEL and a  specific  FIRMWARE  ver-
              sion.

       -B [+]FILE, --drivedb=[+]FILE
              [ATA  only] Read the drive database from FILE.  The new database
              replaces the built in database by default.  If '+' is specified,
              then the new entries prepend the built in entries.

              Optional  entries are read from the file /etc/smart_drivedb.h if
              this option is not specified.

              If /var/lib/smartmontools/drivedb/drivedb.h is present, the con-
              tents of this file is used instead of the built in table.

              Run  /usr/sbin/update-smart-drivedb to update this file from the
              smartmontools SVN repository.

              The database files use the same C/C++ syntax  that  is  used  to
              initialize  the  built  in database array.  C/C++ style comments
              are allowed.  Example:

                /* Full entry: */
                {
                  "Model family",    // Info about model family/series.
                  "MODEL1.*REGEX",   // Regular expression to match model of device.
                  "VERSION.*REGEX",  // Regular expression to match firmware version(s).
                  "Some warning",    // Warning message.
                  "-v 9,minutes"     // String of preset -v and -F options.
                },
                /* Minimal entry: */
                {
                  "",                // No model family/series info.
                  "MODEL2.*REGEX",   // Regular expression to match model of device.
                  "",                // All firmware versions.
                  "",                // No warning.
                  ""                 // No options preset.
                },
                /* USB ID entry: */
                {
                  "USB: Device; Bridge", // Info about USB device and bridge name.
                  "0x1234:0xabcd",   // Regular expression to match vendor:product ID.
                  "0x0101",          // Regular expression to match bcdDevice.
                  "",                // Not used.
                  "-d sat"           // String with device type option.
                },
                /* ... */

       SMART RUN/ABORT OFFLINE TEST AND self-test OPTIONS:

       -t TEST, --test=TEST
              Executes TEST immediately.  The '-C' option can be used in  con-
              junction with this option to run the short or long (and also for
              ATA devices, selective or conveyance) self-tests in captive mode
              (known  as  "foreground mode" for SCSI devices).  Note that only
              one test type can be run at a time, so only one test type should
              be  specified per command line.  Note also that if a computer is
              shutdown or power cycled during a self-test, no harm should  re-
              sult.  The self-test will either be aborted or will resume auto-
              matically.

              All '-t TEST' commands can be given during normal system  opera-
              tion unless captive mode ('-C' option) is used.  A running self-
              test can, however, degrade performance of the  drive.   Frequent
              I/O  requests from the operating system increase the duration of
              a test.  These impacts may vary from device to device.

              If a test failure occurs then the  device  may  discontinue  the
              testing and report the result immediately.

              [ATA] Note that the ATA command SMART EXECUTE OFF-LINE IMMEDIATE
              (the command to start a test) was declared obsolete in ATA ACS-4
              Revision 10 (Nov 2015).

              The valid arguments to this option are:

              offline - [ATA] runs SMART Immediate Offline Test.  This immedi-
              ately starts the test described  above.   This  command  can  be
              given  during normal system operation.  The effects of this test
              are visible only in that it updates the SMART Attribute  values,
              and if errors are found they will appear in the SMART error log,
              visible with the '-l error' option.

              If the '-c' option to smartctl shows that  the  device  has  the
              "Suspend  Offline  collection  upon new command" capability then
              you can track the progress of the Immediate Offline  test  using
              the  '-c'  option to smartctl.  If the '-c' option show that the
              device has the "Abort Offline collection upon new command" capa-
              bility then most commands will abort the Immediate Offline Test,
              so you should not try to track the progress  of  the  test  with
              '-c', as it will abort the test.

              offline  -  [SCSI] runs the default self test in foreground.  No
              entry is placed in the self test log.

              short - [ATA] runs SMART Short Self Test (usually under ten min-
              utes).  This command can be given during normal system operation
              (unless run in captive mode - see the '-C' option below).   This
              is  a  test  in a different category than the immediate or auto-
              matic offline tests.  The "Self" tests check the electrical  and
              mechanical  performance  as  well as the read performance of the
              disk.  Their results are reported in the Self  Test  Error  Log,
              readable with the '-l selftest' option.  Note that on some disks
              the progress of the self-test can be monitored by watching  this
              log  during  the self-test; with other disks use the '-c' option
              to monitor progress.

              short - [SCSI] runs the "Background short" self-test.

              long - [ATA] runs SMART Extended Self Test (tens of  minutes  to
              several  hours).   This is a longer and more thorough version of
              the Short Self Test described above.  Note that this command can
              be  given  during normal system operation (unless run in captive
              mode - see the '-C' option below).

              long - [SCSI] runs the "Background long" self-test.

              conveyance - [ATA only] runs a SMART Conveyance Self Test  (min-
              utes).   This  self-test  routine is intended to identify damage
              incurred during transporting of the device.  This self-test rou-
              tine should take on the order of minutes to complete.  Note that
              this command can be given during normal system operation (unless
              run in captive mode - see the '-C' option below).

              select,N-M,  select,N+SIZE  -  [ATA only] runs a SMART Selective
              Self Test, to test a  range  of  disk  Logical  Block  Addresses
              (LBAs), rather than the entire disk.  Each range of LBAs that is
              checked is called a "span" and is specified by  a  starting  LBA
              (N)  and  an ending LBA (M) with N less than or equal to M.  The
              range can also be specified as N+SIZE.  A span at the end  of  a
              disk can be specified by N-max.

              For example the commands:
                smartctl -t select,10-20 /dev/sda
                smartctl -t select,10+11 /dev/sda
              both  runs  a  self  test  on one span consisting of LBAs ten to
              twenty (inclusive).  The command:
                smartctl -t select,100000000-max /dev/sda
              run a self test from LBA 100000000 up to the end  of  the  disk.
              The  '-t'  option  can  be given up to five times, to test up to
              five spans.  For example the command:
                smartctl -t select,0-100 -t select,1000-2000 /dev/sda
              runs a self test on two spans.  The first span consists  of  101
              LBAs  and  the second span consists of 1001 LBAs.  Note that the
              spans can overlap partially or completely, for example:
                smartctl -t select,0-10 -t select,5-15 -t select,10-20 /dev/sda
              The results of the selective self-test  can  be  obtained  (both
              during  and after the test) by printing the SMART self-test log,
              using the '-l selftest' option to smartctl.

              Selective self tests are particularly useful as disk  capacities
              increase: an extended self test (smartctl -t long) can take sev-
              eral hours.  Selective self-tests are helpful if (based on  SYS-
              LOG  error  messages, previous failed self-tests, or SMART error
              log entries) you suspect that a disk is  having  problems  at  a
              particular range of Logical Block Addresses (LBAs).

              Selective  self-tests  can be run during normal system operation
              (unless done in captive mode - see the '-C' option below).

              The following variants of the selective  self-test  command  use
              spans  based on the ranges from past tests already stored on the
              disk:

              select,redo[+SIZE] - [ATA only] redo the  last  SMART  Selective
              Self Test using the same LBA range.  The starting LBA is identi-
              cal to the LBA used by last test, same for ending LBA  unless  a
              new span size is specified by optional +SIZE argument.

              For example the commands:
                smartctl -t select,10-20 /dev/sda
                smartctl -t select,redo /dev/sda
                smartctl -t select,redo+20 /dev/sda
              have the same effect as:
                smartctl -t select,10-20 /dev/sda
                smartctl -t select,10-20 /dev/sda
                smartctl -t select,10-29 /dev/sda

              select,next[+SIZE] - [ATA only] runs a SMART Selective Self Test
              on the LBA range which follows the range of the last test.   The
              starting  LBA is set to (ending LBA +1) of the last test.  A new
              span size may be specified by the optional +SIZE argument.

              For example the commands:
                smartctl -t select,0-999 /dev/sda
                smartctl -t select,next /dev/sda
                smartctl -t select,next+2000 /dev/sda
              have the same effect as:
                smartctl -t select,0-999 /dev/sda
                smartctl -t select,1000-1999 /dev/sda
                smartctl -t select,2000-3999 /dev/sda

              If the last test ended at the last LBA  of  the  disk,  the  new
              range starts at LBA 0.  The span size of the last span of a disk
              is adjusted such that the total number of  spans  to  check  the
              full  disk  will  not  be  changed  by  future  uses  of '-t se-
              lect,next'.

              select,cont[+SIZE] - [ATA only] performs a 'redo' (above) if the
              self  test  status reports that the last test was aborted by the
              host.  Otherwise it run the 'next' (above) test.

              afterselect,on - [ATA only] perform an offline read scan after a
              Selective self-test has completed.  This option must be used to-
              gether with one or more of the select,N-M options above.  If the
              LBAs  that  have  been specified in the Selective self-test pass
              the test with no errors found, then read scan the  remainder  of
              the  disk.  If the device is powered-cycled while this read scan
              is in progress, the read scan will be automatically resumed  af-
              ter  a  time  specified  by  the pending timer (see below).  The
              value of this option is preserved between selective self-tests.

              afterselect,off - [ATA only] do not read scan the  remainder  of
              the disk after a Selective self-test has completed.  This option
              must be use together with one or more of the select,N-M  options
              above.   The value of this option is preserved between selective
              self-tests.

              pending,N - [ATA only] set the pending offline read  scan  timer
              to N minutes.  Here N is an integer in the range from 0 to 65535
              inclusive.  If the device is powered off during a read scan  af-
              ter  a Selective self-test, then resume the test automatically N
              minutes after power-up.  This option must be use  together  with
              one  or more of the select,N-M options above.  The value of this
              option is preserved between selective self-tests.

              vendor,N - [ATA only] issues the ATA command SMART EXECUTE  OFF-
              LINE  IMMEDIATE with subcommand N in LBA LOW register.  The sub-
              command is specified as a hex value in the range 0x00  to  0xff.
              Subcommands 0x40-0x7e and 0x90-0xff are reserved for vendor spe-
              cific use, see table 61 of T13/1699-D  Revision  6a  (ATA8-ACS).
              Note  that  the  subcommands 0x00-0x04, 0x7f, 0x81-0x84 are sup-
              ported by other smartctl options (e.g. 0x01: '-t  short',  0x7f:
              '-X', 0x82: '-C -t long').

              WARNING:  Only  run  subcommands documented by the vendor of the
              device.

              Example for some Intel SSDs only: The subcommand 0x40 ('-t  ven-
              dor,0x40')  clears  the  timed workload related SMART attributes
              (226, 227, 228).  Note that the raw values of  these  attributes
              are  held  at 65535 (0xffff) until the workload timer reaches 60
              minutes.

              force - start new self-test even if another test is already run-
              ning.  By default a running self-test will not be interrupted to
              begin another test.

       -C, --captive
              [ATA] Runs self-tests in captive mode.  This has no effect  with
              '-t offline' or if the '-t' option is not used.

              WARNING:  Tests  run  in captive mode may busy out the drive for
              the length of the test.  Only run captive tests on drives  with-
              out any mounted partitions!

              [SCSI] Runs the self-test in "Foreground" mode.

       -X, --abort
              Aborts  non-captive  SMART  Self  Tests.  Note that this command
              will abort the Offline Immediate Test routine only if your  disk
              has the "Abort Offline collection upon new command" capability.

ATA, SCSI command sets and SAT
       In  the past there has been a clear distinction between storage devices
       that used the ATA and SCSI command sets.  This  distinction  was  often
       reflected in their device naming and hardware.  Now various SCSI trans-
       ports (e.g. SAS, FC and iSCSI) can  interconnect  to  both  SCSI  disks
       (e.g.  FC  and SAS) and ATA disks (especially SATA).  USB and IEEE 1394
       storage devices use the SCSI command set externally but  almost  always
       contain  ATA  or SATA disks (or flash).  The storage subsystems in some
       operating systems have started to remove the  distinction  between  ATA
       and SCSI in their device naming policies.

       99%  of  operations  that an OS performs on a disk involve the SCSI IN-
       QUIRY, READ CAPACITY, READ and WRITE commands,  or  their  ATA  equiva-
       lents.   Since  the  SCSI commands are slightly more general than their
       ATA equivalents, many OSes are generating SCSI  commands  (mainly  READ
       and WRITE) and letting a lower level translate them to their ATA equiv-
       alents as the need arises.  An  important  note  here  is  that  "lower
       level" may be in external equipment and hence outside the control of an
       OS.

       SCSI to ATA Translation (SAT) is a standard (ANSI INCITS 431-2007) that
       specifies how this translation is done.  For the other 1% of operations
       that an OS performs on a disk, SAT provides two options.  First  is  an
       optional  ATA  PASS-THROUGH SCSI command (there are two variants).  The
       second is a translation from the closest SCSI  command.   Most  current
       interest is in the "pass-through" option.

       The  relevance to smartmontools (and hence smartctl) is that its inter-
       actions with disks fall solidly into the "1%" category.  So even if the
       OS  can  happily treat (and name) a disk as "SCSI", smartmontools needs
       to detect the native command set and act accordingly.  As more  storage
       manufacturers  (including external SATA drives) comply with SAT, smart-
       montools is able to automatically distinguish the native command set of
       the device.  In some cases the '-d sat' option is needed on the command
       line.

       There are also virtual disks which typically have no useful information
       to  convey  to  smartmontools, but could conceivably in the future.  An
       example of a virtual disk is the OS's view of a RAID 1 box.  There  are
       most  likely two SATA disks inside a RAID 1 box.  Addressing those SATA
       disks from a distant OS is a challenge for smartmontools.  Another  ap-
       proach is running a tool like smartmontools inside the RAID 1 box (e.g.
       a Network Attached Storage (NAS) box)  and  fetching  the  logs  via  a
       browser.

EXAMPLES
       smartctl -a /dev/sda
       Print a large amount of SMART information for drive /dev/sda.

       smartctl -s off /dev/sdd
       Disable SMART monitoring and data log collection on drive /dev/sdd.

       smartctl --smart=on --offlineauto=on --saveauto=on /dev/sda
       Enable  SMART on drive /dev/sda, enable automatic offline testing every
       four hours, and enable autosaving of SMART Attributes.  This is a  good
       start-up line for your system's init files.  You can issue this command
       on a running system.

       smartctl -t long /dev/sdc
       Begin an extended self-test of drive /dev/sdc.  You can issue this com-
       mand on a running system.  The results can be seen in the self-test log
       visible with the '-l selftest' option after it has completed.

       smartctl -s on -t offline /dev/sda
       Enable SMART on the disk, and begin an immediate offline test of  drive
       /dev/sda.  You can issue this command on a running system.  The results
       are only used to update the SMART Attributes, visible with the '-A' op-
       tion.   If  any device errors occur, they are logged to the SMART error
       log, which can be seen with the '-l error' option.

       smartctl -A -v 9,minutes /dev/sda
       Shows the vendor Attributes, when the disk stores its power-on time in-
       ternally in minutes rather than hours.

       smartctl -q errorsonly -H -l selftest /dev/sda
       Produces  output only if the device returns failing SMART status, or if
       some of the logged self-tests ended with errors.

       smartctl -q silent -a /dev/sda
       Examine all SMART data for device /dev/sda, but produce no printed out-
       put.  You must use the exit status (the $?  shell variable) to learn if
       any Attributes are out of bound, if the SMART  status  is  failing,  if
       there  are errors recorded in the self-test log, or if there are errors
       recorded in the disk error log.

       smartctl -a -d 3ware,0 /dev/twl0
       Examine all SMART data for the first SATA (not SAS) disk connected to a
       3ware RAID 9750 controller card.

       smartctl -t long -d areca,4 /dev/sg2
       Start  a  long  self-test on the fourth SATA disk connected to an Areca
       RAID controller addressed by /dev/sg2.

       smartctl -a -d hpt,1/3 /dev/sda (under Linux)
       smartctl -a -d hpt,1/3 /dev/hptrr (under FreeBSD)
       Examine all SMART data for the (S)ATA disk directly  connected  to  the
       third channel of the first HighPoint RocketRAID controller card.

       smartctl -t short -d hpt,1/1/2 /dev/sda (under Linux)
       smartctl -t short -d hpt,1/1/2 /dev/hptrr (under FreeBSD)
       Start  a  short self-test on the (S)ATA disk connected to second pmport
       on the first channel of the first HighPoint RocketRAID controller card.

       smartctl -t select,10-100 -t select,30-300 -t afterselect,on  -t  pend-
       ing,45 /dev/sda
       Run  a  selective self-test on LBAs 10 to 100 and 30 to 300.  After the
       these LBAs have been tested, read-scan the remainder of the  disk.   If
       the  disk is power-cycled during the read-scan, resume the scan 45 min-
       utes after power to the device is restored.

       smartctl -a -d cciss,0 /dev/cciss/c0d0
       Examine all SMART data for the first SCSI disk  connected  to  a  cciss
       RAID controller card.

EXIT STATUS
       The exit statuses of smartctl are defined by a bitmask.  If all is well
       with the disk, the exit status (return value) of  smartctl  is  0  (all
       bits  turned  off).  If a problem occurs, or an error, potential error,
       or fault is detected, then a non-zero  status  is  returned.   In  this
       case,  the  eight  different bits in the exit status have the following
       meanings for ATA disks; some of these values may also be  returned  for
       SCSI disks.

       Bit 0: Command line did not parse.

       Bit 1: Device  open  failed,  device  did not return an IDENTIFY DEVICE
              structure, or device is in a low-power  mode  (see  '-n'  option
              above).

       Bit 2: Some SMART or other ATA command to the disk failed, or there was
              a checksum error in a SMART  data  structure  (see  '-b'  option
              above).

       Bit 3: SMART status check returned "DISK FAILING".

       Bit 4: We found prefail Attributes <= threshold.

       Bit 5: SMART  status  check  returned  "DISK OK" but we found that some
              (usage or prefail) Attributes have been  <=  threshold  at  some
              time in the past.

       Bit 6: The device error log contains records of errors.

       Bit 7: The device self-test log contains records of errors.  [ATA only]
              Failed self-tests outdated by a newer successful extended  self-
              test are ignored.

       To  test  within  the  shell  for whether or not the different bits are
       turned on or off, you can use the following type of construction (which
       should work with any POSIX compatible shell):
       smartstat=$(($? & 8))
       This  looks at only at bit 3 of the exit status $?  (since 8=2^3).  The
       shell variable $smartstat will be nonzero if  SMART  status  check  re-
       turned "disk failing" and zero otherwise.

       This shell script prints all status bits:
       val=$?; mask=1
       for i in 0 1 2 3 4 5 6 7; do
         echo "Bit $i: $(((val & mask) && 1))"
         mask=$((mask << 1))
       done

FILES
       /usr/sbin/smartctl
              full path of this executable.

       /var/lib/smartmontools/drivedb/drivedb.h
              drive database (see '-B' option).

       /etc/smart_drivedb.h
              optional local drive database (see '-B' option).

AUTHORS
       Bruce Allen (project initiator),
       Christian  Franke  (project  manager,  Windows  port  and  all  sort of
       things),
       Douglas Gilbert (SCSI subsystem),
       Volker Kuhlmann (moderator of support and database mailing list),
       Gabriele Pohl (wiki & development team support),
       Alex Samorukov (FreeBSD port and more, new Trac wiki).

       Many other individuals have made contributions and corrections, see AU-
       THORS, ChangeLog and repository files.

       The  first  smartmontools code was derived from the smartsuite package,
       written by Michael Cornwell and Andre Hedrick.

REPORTING BUGS
       To submit a bug report, create a ticket in smartmontools wiki:
       <https://www.smartmontools.org/>.
       Alternatively send the info to the smartmontools support mailing list:
       <https://listi.jpberlin.de/mailman/listinfo/smartmontools-support>.

SEE ALSO
       smartd(8).
       update-smart-drivedb(8).

REFERENCES
       Please see the following web site for more info: <https://www.smartmon-
       tools.org/>

       An  introductory  article  about smartmontools is Monitoring Hard Disks
       with SMART, by Bruce Allen, Linux Journal, January 2004,  pages  74-77.
       See <https://www.linuxjournal.com/article/6983>.

       If  you  would  like  to understand better how SMART works, and what it
       does, a good place to start is with Sections 4.8 and 6.54 of the  first
       volume  of  the  'AT  Attachment with Packet Interface-7' (ATA/ATAPI-7)
       specification Revision 4b.   This  documents  the  SMART  functionality
       which the smartmontools utilities provide access to.

       The  functioning of SMART was originally defined by the SFF-8035i revi-
       sion 2 and the SFF-8055i revision 1.4 specifications.  These are publi-
       cations of the Small Form Factors (SFF) Committee.

       Links  to  these  and other documents may be found on the Links page of
       the smartmontools Wiki at <https://www.smartmontools.org/wiki/Links>.

PACKAGE VERSION
       smartmontools-7.1 2019-12-30 r5022
       $Id: smartctl.8.in 5018 2019-12-29 13:37:25Z chrfranke $

smartmontools-7.1                 2019-12-30                       SMARTCTL(8)
Man Pages Copyright Respective Owners. Site Copyright (C) 1994 - 2024 Hurricane Electric. All Rights Reserved.