smartctl [options] device
smartmontools-6.2 2013-07-26 r3841
[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-2, ATA8-ACS, ATA/ATAPI-7 and earlier standards (see REFERENCES
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'
option (for more information see the section on "ATA, SCSI command sets
and SAT" below). Device paths are as follows:
LINUX: Use the forms "/dev/hd[a-t]" for IDE/ATA devices, and
"/dev/sd[a-z]" for SCSI devices. For SCSI Tape Drives and
Changers with TapeAlert support use the devices "/dev/nst*"
and "/dev/sg*". For SATA disks accessed with libata, use
"/dev/sd[a-z]" and append "-d ata". 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 details below. For
disks behind HighPoint RocketRAID controllers 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 controllers, 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
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
The options are grouped below into several categories. smartctl will
execute the corresponding commands in the order: INFORMATION,
ENABLE/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.
Please include this information if you are reporting bugs or
Prints the device model number, serial number, firmware version,
and ATA Standard version/revision information. Says if the
device 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 is 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.
[ATA only] [NEW EXPERIMENTAL SMARTCTL FEATURE] Prints an anno-
tated 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 printing 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 '--identify=wb' (all words, all
bits) produces the longest output.
Prints all SMART information about the disk, or TapeAlert infor-
mation about the tape drive or changer. For ATA devices this is
-l selective -l directory -l scttemp -l scterc -l devstat -l sataphy'.
and for SCSI, this is equivalent to
'-H -i -A -l error -l selftest -l background -l sasphy'.
--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.
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-
smartctl --scan-open -- -a -W 4,45,50 -m admin@work > smartd.conf
-g NAME, --get=NAME
Get non-SMART device settings. See '-s, --set' below for fur-
RUN-TIME BEHAVIOR OPTIONS:
-q TYPE, --quietmode=TYPE
Specifies that smartctl should run in one of the two quiet modes
described 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'
option, 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 RETURN VALUES
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
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
(SAT). This is for ATA disks that have a SCSI to ATA Transla-
tion (SAT) Layer (SATL) between the disk and the operating sys-
tem. 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
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
default. 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
appear under separate /dev/ice names then. CAUTION: Specifying
',x' for a device which does not support it results in I/O
errors and may disconnect the drive. The same applies if the
specified PORT does not exist or is not connected to a disk.
[NEW EXPERIMENTAL SMARTCTL FEATURE] The Prolific PL2507/3507 USB
bridges with older firmware support a pass-through command simi-
lar to JMicron and work with '-d usbjmicron,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.
usbsunplus - this device type is for SATA disks that are behind
a SunplusIT USB to SATA bridge.
marvell - [Linux only] interact with SATA disks behind Marvell
chip-set controllers (using the Marvell rather than libata
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
denotes which disk on the controller is monitored. Use syntax
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 and
/dev/twe0-15, may be used with 3ware series 6000, 7000, and 8000
series controllers that use the 3x-xxxx driver. Note that the
/dev/sda-z form is deprecated starting with the Linux 2.6 kernel
series and may not be supported by the Linux kernel in the near
future. The final form, which refers to devices /dev/twa0-15,
must be used with 3ware 9000 series controllers, which use the
The devices /dev/twl0-15 [Linux] or /dev/tws0-15 [FreeBSD] must
be used with the 3ware/LSI 9750 series controllers which use the
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. Typically /dev/twa0 refers to the first 9000-series con-
troller, /dev/twa1 refers to the second 9000 series controller,
and so on. The /dev/twl0 devices refers to the first 9750
series controller, /dev/twl1 resfers to the second 9750 series
controller, and so on. Likewise /dev/twe0 refers to the first
6/7/8000-series controller, /dev/twe1 refers to the second
6/7/8000 series controller, and so on.
Note that for the 6/7/8000 controllers, any of the physical
disks can be queried or examined using any of the 3ware's SCSI
logical device /dev/sd? entries. Thus, if logical device
/dev/sda is made up of two physical disks (3ware ports zero and
one) and logical device /dev/sdb is made up of two other physi-
cal disks (3ware ports two and three) then you can examine the
SMART data on any of the four physical disks using either SCSI
device /dev/sda or /dev/sdb. If you need to know which logical
SCSI device a particular physical disk (3ware port) is associ-
ated with, use the dmesg or SYSLOG output to show which SCSI ID
corresponds to a particular 3ware unit, and then use the 3ware
CLI or 3dm tool to determine which ports (physical disks) corre-
spond to particular 3ware units.
If the value of N corresponds to a port that does not exist on
the 3ware controller, or to a port that does not physically have
a disk attached to it, the behavior of smartctl depends upon the
specific controller model, firmware, Linux kernel and platform.
In some cases you will get a warning message that the device
does not exist. In other cases you will be presented with
'void' data for a non-existent device.
Note that if the /dev/sd? addressing form is used, then older
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
devices 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] [NEW
EXPERIMENTAL SMARTCTL FEATURE] the device consists of one or
more SATA or SAS disks connected to an Areca SAS RAID con-
troller. The integer N (range 1 to 128) denotes the channel
(slot) and E (range 1 to 8) denotes the enclosure. Important:
This requires Areca SAS controller firmware version 1.51 or
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.
To look at disks behind HP Smart Array controllers, use syntax
smartctl -a -d cciss,0 /dev/cciss/c0d0 (cciss driver under Linux)
smartctl -a -d cciss,0 /dev/sg2 (hpsa or hpahcisr drivers under 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-
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
ENABLE/DISABLE, and (4) SMART RETURN STATUS.
The valid arguments to this option are:
normal - exit on failure of any mandatory SMART command, and
ignore all failures of optional SMART commands. This is the
default. Note that on some devices, issuing unimplemented
optional 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
ignored. 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
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
detail of these ioctl() transactions are reported in greater
detail. The valid arguments to this option are:
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, --nocheck=POWERMODE
[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. A nonzero exit status is returned
if the device is in one of the specified low-power modes (see
RETURN VALUES below).
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.
The valid arguments to this option are:
never - check the device always, but print the power mode if
'-i' is specified.
sleep - check the device unless it is in SLEEP mode.
standby - 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
idle - 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
issued. The enable command will always be issued before the
corresponding disable command.
-s VALUE, --smart=VALUE
Enables or disables SMART on device. The valid arguments to
this option are on and off. Note that the command '-s on' (per-
haps used with with the '-o on' and '-S on' options) should be
placed in a start-up script for your machine, for example in
rc.local or rc.sysinit. In principle the SMART feature settings
are preserved over power-cycling, but it doesn't hurt to be
specification, but was never part of any ATA specification.
However it is implemented and used by many vendors. [Good docu-
mentation can be found in IBM's Official Published Disk Specifi-
cations. For example the IBM Travelstar 40GNX Hard Disk Drive
Specifications (Revision 1.1, 22 April 2002, Publication # 1541,
Document S07N-7715-02) page 164. You can also read the SFF-8035i
Specification -- see REFERENCES below.] You can tell if auto-
matic offline testing is supported by seeing if this command
enables and disables it, as indicated by the 'Auto Offline Data
Collection' part of the SMART capabilities report (displayed
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 performance.
The '-o on' option causes this offline testing to be carried
out, automatically, on a regular scheduled basis. Normally, the
disk will suspend offline testing while disk accesses are taking
place, and then automatically resume it when the disk would oth-
erwise be idle, so in practice it has little effect. Note that
a one-time offline test can also be carried out immediately upon
receipt of a user command. See the '-t offline' option below,
which causes a one-time offline test to be carried out immedi-
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 visible
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;
[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
cycles, 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
unable to print a warning if autosave is disabled.
[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 pre-
vents 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 applications
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'
option shares its short option '-s' with '--smart'. Valid argu-
all - Gets all values. This is equivalent to
'-g aam -g apm -g lookahead -g security -g wcache'
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
lookahead[,on|off] - [ATA only] Gets/sets the read look-ahead
feature (if supported). Read look-ahead is usually enabled by
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.
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.
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.
wcache[,on|off] - [ATA] Gets/sets the volatile write cache fea-
ture (if supported). The write cache is usually enabled by
wcache[,on|off] - [SCSI] [NEW EXPERIMENTAL SMARTCTL FEATURE]
Gets/sets the 'Write Cache Enable' (WCE) bit (if supported).
The write cache is usually enabled by default.
wcreorder[,on|off] - [ATA only] [NEW EXPERIMENTAL SMARTCTL FEA-
TURE] Gets/sets Write Cache Reordering. If it is disabled
(off), disk write scheduling is executed on a first-in-first-out
(FIFO) basis. If Write Cache Reordering is enabled (on), then
disk write scheduling may be reordered 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 received. The state of Write Cache
Reordering has no effect on either NCQ or LCQ queued commands.
rcache[,on|off] - [SCSI only] [NEW EXPERIMENTAL SMARTCTL FEA-
TURE] Gets/sets the 'Read Cache Disable' (RCE) bit. 'Off' value
disables read cache (if supported). The read cache is usually
enabled by default.
SMART READ AND DISPLAY DATA OPTIONS:
Check: Ask the device to report its SMART health status or pend-
ing TapeAlert messages. SMART status is based on information
that it has gathered from online and offline tests, which were
used to determine/update its SMART vendor-specific Attribute
values. TapeAlert status is obtained by reading the TapeAlert
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 only] Prints only the generic SMART capabilities. These
show what SMART features are implemented and how the device will
respond to some of the different SMART commands. For example it
shows if the device logs errors, if it supports offline surface
[ATA] Prints only the vendor specific SMART Attributes. The
Attributes 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-
cycled, 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
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"
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.
"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
operations 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
attributes. In this case the attribute name printed by smartctl
is incorrect unless the drive is already in the smartmontools
[SCSI] For SCSI devices the "attributes" are obtained from the
temperature and start-stop cycle counter log pages. Certain ven-
dor specific attributes are listed if recognised. The attributes
are output in a relatively free format (compared with ATA disk
-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 colums (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 either the SMART Error Log, the SMART Self-Test Log, the
SMART Selective Self-Test Log [ATA only], the Log Directory [ATA
only], or the Background Scan Results Log [SCSI only]. The
valid arguments to this option are:
error - [ATA] prints the Summary SMART error log. SMART disks
ILI: (packet command-set specific)
MC: Media Changed
MCR: Media Change Request
NM: No Media
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
error 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
notation [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 none-
theless; these are marked [NS], meaning non-standard.
The ATA Specification (ATA-5 Revision 1c, Section 220.127.116.11.2)
says: "Error log structures shall include UNC errors, IDNF
errors for which the address requested was valid, servo errors,
write fault errors, etc. Error log data structures shall not
include errors attributed to the receipt of faulty commands such
as command codes not implemented by the device or requests with
invalid parameters or invalid addresses." 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
effect, 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
address to the name of the disk file containing the erroneous
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, typical values for HDD
are 2 (Samsung), 5 (Seagate) or 6 (WD).
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
error log is not supported, the Summary SMART self-test log is
Please note that recent drives may report errors only in the
Extended 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. On Linux systems
the smartmontools web page has instructions about how to convert
this LBA address to the name of the disk file containing the
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
describe the type of the test. The printed segment number is
only relevant when a test fails in the third or later test seg-
ment. 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 nota-
tion. On Linux systems the smartmontools web page has instruc-
tions about how to convert this LBA address to the name of the
disk file containing the erroneous block. If provided, the SCSI
Sense Key (SK), Additional Sense Code (ASC) and Additional Sense
Code Qualifier (ASQ) are also printed. The self tests can be run
using the '-t' option described below (using the ATA test termi-
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 errors. 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
introduced in ATA8-ACS and were also supported by many ATA-7
scttempint,N[,p] - [ATA only] clears the SCT temperature history
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 (e.g. Hitachi
7K3000, Intel 320, 330, 520 and 710 Series SSDs, Crucial/Micron
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
reset 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.
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.
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
endurance indicator. A value of 0 indicates as new condition
while 100 indicates the device is at the end of its lifetime as
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
default 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
attribute 5 with big endian instead of little endian byte order-
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
raw16 - Print the Raw value as three 16-bit unsigned base-10
integers. This may be useful for decoding the meaning of the
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
hex56 - Print the Raw value as a 14 digit hexadecimal number.
This includes the reserved byte which follows the 48-bit raw
raw64 - Print the Raw value as a 64-bit unsigned base-10 inte-
ger. This includes two bytes from the normalized and worst
attribute 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-
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
always printed with two digits, for example "06" or "31" or
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
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
mechanical 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:
193,loadunload - same as: 193,raw24/raw24.
tor Count) is not reset if uncorrectable sectors are reallocated
(see smartd.conf(5) man page).
198,offlinescanuncsectorct - same as: 198,raw48,Off-
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.
Note: a table of hard drive models, listing which Attribute cor-
responds to temperature, can be found at:
-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 over-ride any preset values.
nologdir - Suppresses read attempts of SMART or GP Log Direc-
tory. Support for all standard logs is assumed without an
actual check. Some Intel SSDs may freeze if log address 0 is
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
reported 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
appear 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
[ATA only] Specifies whether smartctl should use any preset
options that are available for this drive. By default, if the
drive is recognized in the smartmontools database, then the pre-
sets are used.
smartctl can automatically set appropriate options for known
drives. For example, the Maxtor 4D080H4 uses Attribute 9 to
stores power-on time in minutes whereas most drives use that
Attribute to store the power-on time in hours. The command-line
option '-v 9,minutes' ensures that smartctl correctly interprets
Attribute 9 in this case, but that option is preset for the Max-
tor 4D080H4 and so need not be specified by the user on the
smartctl command line.
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
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-
-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.
/* 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
result. The self-test will either be aborted or will resume
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.
The valid arguments to this option are:
offline - [ATA] runs SMART Immediate Offline Test. This immedi-
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).
This is a longer and more thorough version of the Short Self
Test described above. Note that this command can be given dur-
ing 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/hda
smartctl -t select,10+11 /dev/hda
both runs a self test on one span consisting of LBAs ten to
twenty (inclusive). The command:
smartctl -t select,100000000-max /dev/hda
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/hda
runs a self test on two spans. The first span consists of 101
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
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/hda
smartctl -t select,redo /dev/hda
smartctl -t select,redo+20 /dev/hda
have the same effect as:
smartctl -t select,10-20 /dev/hda
smartctl -t select,10-20 /dev/hda
smartctl -t select,10-29 /dev/hda
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/hda
smartctl -t select,next /dev/hda
smartctl -t select,next+2000 /dev/hda
have the same effect as:
smartctl -t select,0-999 /dev/hda
smartctl -t select,1000-1999 /dev/hda
smartctl -t select,2000-3999 /dev/hda
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
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
together 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
after 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 supported
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
Example for Intel (X18/X25-M G2, 320, 520 and 710 Series) SSDs
only: The subcommand 0x40 ('-t vendor,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.
[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.
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
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
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
approach is running a tool like smartmontools inside the RAID 1 box
(e.g. a Network Attached Storage (NAS) box) and fetching the logs via
smartctl -a /dev/hda
Print a large amount of SMART information for drive /dev/hda which is
typically an ATA (IDE) or SATA disk in Linux.
smartctl -a /dev/sdb
Print a large amount of SMART information for drive /dev/sdb . This may
be a SCSI disk or an ATA (SATA) disk.
smartctl -s off /dev/hdd
Disable SMART monitoring and data log collection on drive /dev/hdd .
smartctl --smart=on --offlineauto=on --saveauto=on /dev/hda
Enable SMART on drive /dev/hda, 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/hdc
Begin an extended self-test of drive /dev/hdc. 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/hda
Enable SMART on the disk, and begin an immediate offline test of drive
/dev/hda. You can issue this command on a running system. The results
are only used to update the SMART Attributes, visible with the '-A'
option. 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/hda
Shows the vendor Attributes, when the disk stores its power-on time
internally in minutes rather than hours.
Examine all SMART data for the first ATA disk connected to a 3ware RAID
smartctl -a -d 3ware,0 /dev/twe0
Examine all SMART data for the first ATA disk connected to a 3ware RAID
6000/7000/8000 controller card.
smartctl -a -d 3ware,0 /dev/twa0
Examine all SMART data for the first ATA disk connected to a 3ware RAID
9000 controller card.
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 short -d 3ware,3 /dev/sdb
Start a short self-test on the fourth ATA disk connected to the 3ware
RAID controller card which is the second SCSI device /dev/sdb.
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 pending,45 /dev/hda
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.
The return values of smartctl are defined by a bitmask. If all is well
with the disk, the return value (exit status) 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 return value have the following
meanings for ATA disks; some of these values may also be returned for
Bit 0: Command line did not parse.
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 (this
is bash syntax):
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
returned "disk failing" and zero otherwise.
This bash script prints all status bits:
for ((i=0; i<8; i++)); do
echo "Bit $i: $((status & 2**i && 1))"
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 condi-
University of Wisconsin - Milwaukee Physics Department
Christian Franke (Windows interface, C++ redesign, most enhancements
The following have made large contributions to smartmontools:
Casper Dik (Solaris SCSI interface)
Douglas Gilbert (SCSI subsystem)
Guido Guenther (Autoconf/Automake packaging)
Geoffrey Keating (Darwin ATA interface)
Eduard Martinescu (FreeBSD interface)
Frederic L. W. Meunier (Web site and Mailing list)
Gabriele Pohl (Web site and Wiki, conversion from CVS to SVN)
Keiji Sawada (Solaris ATA interface)
Manfred Schwarb (Drive database)
Sergey Svishchev (NetBSD interface)
David Snyder and Sergey Svishchev (OpenBSD interface)
Phil Williams (User interface and drive database)
HOME PAGE FOR SMARTMONTOOLS:
Please see the following web site for updates, further documentation,
bug reports and patches: http://smartmontools.sourceforge.net/
smartd(8), badblocks(8), ide-smart(8).
REFERENCES FOR SMART
An introductory article about smartmontools is Monitoring Hard Disks
with SMART, by Bruce Allen, Linux Journal, January 2004, pages 74-77.
This is http://www.linuxjournal.com/article/6983 online.
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 http://sourceforge.net/apps/trac/smartmon-
SVN ID OF THIS PAGE:
$Id: smartctl.8.in 3832 2013-07-20 14:49:31Z chrfranke $
smartmontools-6.2 2013-07-26 SMARTCTL(8)
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