dmsetup clear device_name
       dmsetup create device_name [-u uuid] [--notable|--table <table>|
              table_file] [{--addnodeoncreate|--addnodeonresume}] [--readahead
       dmsetup deps [-o options] [device_name]
       dmsetup help [-c|-C|--columns]
       dmsetup info [device_name]
       dmsetup info -c|-C|--columns [--noheadings] [--separator separator]
              [-o fields] [-O|--sort sort_fields] [device_name]
       dmsetup load device_name [--table <table>|table_file]
       dmsetup ls [--target target_type] [--exec command] [--tree] [-o
       dmsetup message device_name sector message
       dmsetup mknodes [device_name]
       dmsetup mangle [device_name]
       dmsetup reload device_name [--table <table>|table_file]
       dmsetup wipe_table device_name
       dmsetup remove [-f|--force] [--retry] device_name
       dmsetup remove_all [-f|--force]
       dmsetup rename device_name new_name
       dmsetup rename device_name --setuuid uuid
       dmsetup resume device_name [{--addnodeoncreate|--addnodeonresume}]
              [--readahead [+]<sectors>|auto|none]
       dmsetup setgeometry device_name cyl head sect start
       dmsetup splitname device_name [subsystem]
       dmsetup status [--target target_type] [--noflush] [device_name]
       dmsetup suspend [--nolockfs] [--noflush] device_name
       dmsetup table [--target target_type] [--showkeys] [device_name]
       dmsetup targets
       dmsetup udevcomplete cookie
       dmsetup udevcomplete_all [age_in_minutes]
       dmsetup udevcookies
       dmsetup udevcreatecookie
       dmsetup udevflags cookie
       dmsetup udevreleasecookie [cookie]
       dmsetup version
       dmsetup wait [--noflush] device_name [event_nr]

       devmap_name major minor
       devmap_name major:minor

       dmsetup  manages  logical  devices  that  use the device-mapper driver.
       Devices are created by loading a table that specifies a target for each
       sector (512 bytes) in the logical device.

       The first argument to dmsetup is a command.  The second argument is the
       logical device name or uuid.

       Invoking the command as devmap_name is equivalent to
       dmsetup info -c --noheadings -j major -m minor.

              Display output in columns rather than as Field: Value lines.

              Outputs  a summary of the commands available, optionally includ-
              ing the list of report fields (synonym with help command).

              When returning any table information from the kernel  report  on
              the  inactive  table instead of the live table.  Requires kernel
              driver version 4.16.0 or above.

       --manglename <mangling_mode>
              Mangle any character not on a whitelist using mangling_mode when
              processing  device-mapper  device names and UUIDs. The names and
              UUIDs are mangled on input and unmangled  on  output  where  the
              mangling_mode  is one of: none (no mangling), hex (always do the
              mangling) and auto (only do the mangling if not mangled yet,  do
              nothing  if  already  mangled,  error  on mixed; this is used by
              default).  Character whitelist: 0-9, A-Z,  a-z,  #+-.:=@_.  This
              whitelist  is  also  supported  by  udev. Any character not on a
              whitelist is replaced with its hex value (two  digits)  prefixed
              by \x.

       -j|--major major
              Specify the major number.

       -m|--minor minor
              Specify the minor number.

              Suppress the headings line when using columnar output.

              Tell  the  kernel not to supply the open reference count for the

              When creating a device, don't load any table.

              Do not allow udev to manage nodes for devices  in  device-mapper

              Do not synchronise with udev when creating, renaming or removing

              Specify which fields to display.

       --readahead [+]<sectors>|auto|none
              Specify read ahead size in units of sectors.  The default  value
              Use cookie for udev synchronisation.

              Specify the uuid.

              Answer yes to all prompts automatically.

       -v|--verbose [-v|--verbose]
              Produce additional output.

              If udev synchronisation is enabled, verify that udev  operations
              get  performed  correctly  and  try  to  fix up the device nodes
              afterwards if not.

              Display the library and kernel driver version.

       clear  device_name
              Destroys the table in the inactive table slot for device_name.

       create device_name  [-u  uuid]  [--notable|--table  <table>|table_file]
              [{--addnodeoncreate|--addnodeonresume}]   [--readahead  [+]<sec-
              Creates a device with the given name.  If table_file or  <table>
              is supplied, the table is loaded and made live.  Otherwise a ta-
              ble is read from standard input unless --notable is  used.   The
              optional  uuid can be used in place of device_name in subsequent
              dmsetup  commands.   If  successful  a  device  will  appear  as
              /dev/mapper/<device-name>.  See below for information on the ta-
              ble format.

       deps   [-o options] [device_name]
              Outputs a list of devices referenced by the live table  for  the
              specified  device.  Device  names on output can be customised by
              following  options:  devno  (major  and  minor  pair,  used   by
              default),  blkdevname (block device name), devname (map name for
              device-mapper devices, equal to blkdevname otherwise).

       help   [-c|-C|--columns]
              Outputs a summary of the commands available, optionally  includ-
              ing the list of report fields.

       info   [device_name]
              Outputs some brief information about the device in the form:
                      State: SUSPENDED|ACTIVE, READ-ONLY
                      Tables present: LIVE and/or INACTIVE
                      Open reference count
                      Last event sequence number (used by wait)
                      Major and minor device number
                      Number of targets in the live table

              List device names.  Optionally only list devices  that  have  at
              least  one  target  of the specified type.  Optionally execute a
              command for each device.  The device name  is  appended  to  the
              supplied  command.   Device names on output can be customised by
              following  options:  devno  (major  and  minor  pair,  used   by
              default),  blkdevname (block device name), devname (map name for
              device-mapper devices, equal to blkdevname  otherwise).   --tree
              displays  dependencies  between devices as a tree.  It accepts a
              comma-separate list of options.  Some  specify  the  information
              displayed   against   each  node:  device/nodevice;  blkdevname;
              active, open, rw, uuid.  Others specify how  the  tree  is  dis-
              played: ascii, utf, vt100; compact, inverted, notrunc.

       load|reload device_name [--table <table>|table_file]
              Loads  <table>  or  table_file  into the inactive table slot for
              device_name.  If neither is supplied, reads a table  from  stan-
              dard input.

       wipe_table device_name
              Wait  for any I/O in-flight through the device to complete, then
              replace the table with a new table that fails any new  I/O  sent
              to  the  device.  If successful, this should release any devices
              held open by the device's table(s).

       message device_name sector message
              Send message to target. If sector not needed use 0.

       mknodes [device_name]
              Ensure that the node in /dev/mapper for device_name is  correct.
              If  no  device_name  is  supplied,  ensure  that  all  nodes  in
              /dev/mapper correspond to mapped devices currently loaded by the
              device-mapper  kernel driver, adding, changing or removing nodes
              as necessary.

       mangle [device_name]
              Ensure existing device-mapper device name and  UUID  is  in  the
              correct  mangled  form  containing  only  whitelisted characters
              (supported by udev) and do a rename if necessary. Any  character
              not  on  the whitelist will be mangled based on the --manglename
              setting. Automatic rename works only for device  names  and  not
              for  device UUIDs because the kernel does not allow changing the
              UUID of active devices. Any incorrect UUIDs  are  reported  only
              and  they  must be manually corrected by deactivating the device
              first and then reactivating it with proper  mangling  mode  used
              (see also --manglename).

       remove [-f|--force] [--retry] device_name
              Removes  a  device.   It  will  no longer be visible to dmsetup.
              Open devices cannot be removed except with  older  kernels  that
              contain a version of device-mapper prior to 4.8.0.  In this case
              the device will be deleted when its open_count  drops  to  zero.
              From version 4.8.0 onwards, if a device can't be removed because
              an uninterruptible process is waiting for I/O to return from it,
              adding  --force  will  replace the table with one that fails all
              This also runs mknodes afterwards.

       rename device_name new_name
              Renames a device.

       rename device_name --setuuid uuid
              Sets  the  uuid  of  a  device  that was created without a uuid.
              After a uuid has been set it cannot be changed.

       resume device_name [{--addnodeoncreate|--addnodeonresume}] [--readahead
              Un-suspends  a device.  If an inactive table has been loaded, it
              becomes live.  Postponed I/O then gets re-queued for processing.

       setgeometry device_name cyl head sect start
              Sets the device geometry to C/H/S.

       splitname device_name [subsystem]
              Splits given device name into subsystem  constituents.   Default
              subsystem is LVM.

       status [--target target_type] [--noflush] [device_name]
              Outputs  status  information  for  each of the device's targets.
              With --target, only information relating to the specified target
              type  any  is  displayed.  With --noflush, the thin target (from
              version 1.3.0) doesn't commit any outstanding  changes  to  disk
              before reporting its statistics.

       suspend [--nolockfs] [--noflush] device_name
              Suspends  a device.  Any I/O that has already been mapped by the
              device but has not yet completed will be flushed.   Any  further
              I/O  to  that device will be postponed for as long as the device
              is suspended.  If there's a filesystem on the device which  sup-
              ports  the  operation,  an attempt will be made to sync it first
              unless --nolockfs is specified.  Some  targets  such  as  recent
              (October  2006)  versions of multipath may support the --noflush
              option.  This lets outstanding I/O that has not yet reached  the
              device to remain unflushed.

       table  [--target target_type] [--showkeys] [device_name]
              Outputs the current table for the device in a format that can be
              fed back in using the create or load commands.   With  --target,
              only  information  relating to the specified target type is dis-
              played.  Encryption keys are suppressed in the table output  for
              the crypt target unless the --showkeys parameter is supplied.

              Displays the names and versions of the currently-loaded targets.

       udevcomplete cookie
              Wake  any  processes  that are waiting for udev to complete pro-
              cessing the specified cookie.

       udevcomplete_all [age_in_minutes]
              group several actions together and use only one cookie  instead.
              We can define a cookie to use for each relevant command by using
              --udevcookie option. Alternatively, we  can  export  this  value
              into  the  environment  of the dmsetup process as DM_UDEV_COOKIE
              variable and it will be used automatically with  all  subsequent
              commands  until  it is unset.  Invoking this command will create
              system-wide semaphore that needs to be cleaned up explicitly  by
              calling udevreleasecookie command.

       udevflags cookie
              Parses  given  cookie  value and extracts any udev control flags
              encoded.  The output is in environment key format that is  suit-
              able  for  use  in udev rules. If the flag has its symbolic name
              assigned  then  the  output   is   DM_UDEV_FLAG_<flag_name>='1',
              DM_UDEV_FLAG<flag_position>='1' otherwise.  Subsystem udev flags
              don't have symbolic names assigned and  these  ones  are  always
              reported as DM_SUBSYSTEM_UDEV_FLAG<flag_position>='1'. There are
              16 udev flags altogether.

       udevreleasecookie [cookie]
              Waits for all pending udev  processing  bound  to  given  cookie
              value  and clean up the cookie with underlying semaphore. If the
              cookie is not given directly, the command  will  try  to  use  a
              value defined by DM_UDEV_COOKIE environment variable.

              Outputs version information.

       wait   [--noflush] device_name [event_nr]
              Sleeps until the event counter for device_name exceeds event_nr.
              Use -v to see the event number returned.  To wait until the next
              event  is  triggered,  use  info  to find the last event number.
              With --noflush, the thin target  (from  version  1.3.0)  doesn't
              commit any outstanding changes to disk before reporting its sta-

       Each line of the table specifies a single target and is of the form:

       logical_start_sector num_sectors target_type <target_args>

       Simple target types and <target_args> include:

       linear destination_device start_sector
              The traditional linear mapping.

       striped num_stripes chunk_size [destination start_sector]+
              Creates a striped area.
              e.g. striped 2 32 /dev/hda1 0 /dev/hdb1 0  will  map  the  first
              chunk (16k) as follows:
                      LV chunk 1 -> hda1, chunk 1
                      LV chunk 2 -> hdb1, chunk 1
                      LV chunk 3 -> hda1, chunk 2

       More complex targets include:

              Transparent encryption of block devices using the kernel  crypto

              Delays  reads  and/or  writes  to different devices.  Useful for

              Creates a similar mapping to  the  linear  target  but  exhibits
              unreliable  behaviour periodically.  Useful for simulating fail-
              ing devices when testing.

              Mirrors data across two or more devices.

              Mediates access through multiple paths to the same device.

              Offers an interface to the kernel's software raid driver, md.

              Supports snapshots of devices.

       To find out more about the various targets and their table formats  and
       status  lines, please read the files in the Documentation/device-mapper
       directory in the kernel source tree.  (Your distribution might  include
       a  copy  of  this  information  in  the documentation directory for the
       device-mapper package.)

       # A table to join two disks together
       0 1028160 linear /dev/hda 0
       1028160 3903762 linear /dev/hdb 0

       # A table to stripe across the two disks,
       # and add the spare space from
       # hdb to the back of the volume

       0 2056320 striped 2 32 /dev/hda 0 /dev/hdb 0
       2056320 2875602 linear /dev/hdb 1028160

              The device directory name.  Defaults to "/dev" and  must  be  an
              absolute path.


Linux                             Apr 06 2006                       DMSETUP(8)
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