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PVMOVE(8)                            System Manager's Manual                            PVMOVE(8)

NAME
       pvmove — move physical extents

SYNOPSIS
       pvmove [--abort] [--alloc AllocationPolicy] [--atomic] [-b|--background] [--commandprofile
       ProfileName] [-d|--debug] [-h|--help] [-i|--interval  Seconds]  [--noudevsync]  [-v|--ver‐
       bose]  [-n|--name  LogicalVolume]  [SourcePhysicalVolume[:PE[-PE]...]   [DestinationPhysi‐
       calVolume[:PE[-PE]...]...]]

DESCRIPTION
       pvmove allows you to move the allocated physical extents (PEs) on SourcePhysicalVolume  to
       one or more other physical volumes (PVs).  You can optionally specify a source LogicalVol‐
       ume in which case only extents used by that LV  will  be  moved  to  free  (or  specified)
       extents  on  DestinationPhysicalVolume(s).   If no DestinationPhysicalVolume is specified,
       the normal allocation rules for the Volume Group are used.

       If pvmove gets interrupted for any reason (e.g. the machine crashes) then run pvmove again
       without  any  PhysicalVolume arguments to restart any moves that were in progress from the
       last checkpoint.  Alternatively use pvmove --abort at any time to  abort.   The  resulting
       location  of  logical  volumes  after  an  abort is issued depends on whether the --atomic
       option was used when starting the pvmove process.

       You can run more than one pvmove at once provided they are moving data off different Sour‐
       cePhysicalVolumes,  but  additional pvmoves will ignore any Logical Volumes already in the
       process of being changed, so some data might not get moved.

       pvmove works as follows:

       1. A temporary 'pvmove' Logical Volume is created to store details of all the  data  move‐
       ments required.

       2. Every Logical Volume in the Volume Group is searched for contiguous data that need mov‐
       ing according to the command line arguments.  For each piece of data found, a new  segment
       is  added  to the end of the pvmove LV.  This segment takes the form of a temporary mirror
       to copy the data from the original location to a newly-allocated location.   The  original
       LV  is updated to use the new temporary mirror segment in the pvmove LV instead of access‐
       ing the data directly.

       3. The Volume Group metadata is updated on disk.

       4. The first segment of the pvmove Logical Volume is activated and starts  to  mirror  the
       first  part  of  the  data.   Only one segment is mirrored at once as this is usually more
       efficient.

       5. A daemon repeatedly checks progress at the specified time interval.   When  it  detects
       that  the  first  temporary  mirror is in-sync, it breaks that mirror so that only the new
       location for that data gets used and writes a checkpoint into the Volume Group metadata on
       disk.  Then it activates the mirror for the next segment of the pvmove LV.

       6.  When  there  are no more segments left to be mirrored, the temporary Logical Volume is
       removed and the Volume Group metadata is updated so that the Logical Volumes  reflect  the
       new data locations.

       Note  that  this  new  process  cannot support the original LVM1 type of on-disk metadata.
       Metadata can be converted using vgconvert(8).

       If the --atomic option is used, a slightly  different  approach  is  used  for  the  move.
       Again, a temporary 'pvmove' logical volume is created to store the details of all the data
       movements required.  This temporary LV contains all the segments of the various  LVs  that
       need  to  be moved.  However this time, an identical logical volume is allocated that con‐
       tains the same number of segments and a mirror is created to copy the  contents  from  the
       first  temporary  LV  to  the second.  When a complete copy is accomplished, the temporary
       logical volumes are removed, leaving behind the segments on the destination physical  vol‐
       ume.   If  an abort is issued during the move, all logical volumes being moved will remain
       on the source physical volume.

OPTIONS
       See lvm(8) for common options.

       --abort
              Abort any moves in progress.  If the --atomic option was used to start the  pvmove,
              all  logical  volumes  will remain on the source physical volume.  Otherwise, those
              segments that have completed the move will stay on the destination physical volume,
              while those that have not will remain on the source physical volume.

       --atomic
              Make  the  entire operation atomic.  That is, ensure that all affected logical vol‐
              umes are moved to the destination physical volume together;  unless  the  move  has
              been aborted.  If the move has been aborted, all logical volumes will remain on the
              source physical volume.

       --noudevsync
              Disable udev synchronisation. The process will not wait for notification from udev.
              It  will  continue  irrespective of any possible udev processing in the background.
              You should only use this if udev is not  running  or  has  rules  that  ignore  the
              devices LVM2 creates.

       -b, --background
              Run the daemon in the background.

       -i, --interval Seconds
              Report progress as a percentage at regular intervals.

       -n, --name LogicalVolume
              Move  only the extents belonging to LogicalVolume from SourcePhysicalVolume instead
              of all allocated extents to the destination physical volume(s).

Examples
       To move all Physical Extents that are used by simple Logical Volumes on /dev/sdb1 to  free
       Physical Extents elsewhere in the Volume Group use:

       pvmove /dev/sdb1

       Additionally, a specific destination device /dev/sdc1 can be specified like this:

       pvmove /dev/sdb1 /dev/sdc1

       To  perform  the  action  only  on extents belonging to the single Logical Volume lvol1 do
       this:

       pvmove -n lvol1 /dev/sdb1 /dev/sdc1

       Rather than moving the contents of the entire device, it is possible to move  a  range  of
       Physical Extents - for example numbers 1000 to 1999 inclusive on /dev/sdb1 - like this:

       pvmove /dev/sdb1:1000-1999

       A range can also be specified as start+length, so

       pvmove /dev/sdb1:1000+1000

       also refers to 1000 Physical Extents starting from Physical Extent number 1000.  (Counting
       starts from 0, so this refers to the 1001st to the 2000th inclusive.)

       To move a range of Physical Extents to a specific location  (which  must  have  sufficient
       free extents) use the form:

       pvmove /dev/sdb1:1000-1999 /dev/sdc1

       or

       pvmove /dev/sdb1:1000-1999 /dev/sdc1:0-999

       If  the  source and destination are on the same disk, the anywhere allocation policy would
       be needed, like this:

       pvmove --alloc anywhere /dev/sdb1:1000-1999 /dev/sdb1:0-999

       The part of a specific Logical Volume present within in a range of  Physical  Extents  can
       also be picked out and moved, like this:

       pvmove -n lvol1 /dev/sdb1:1000-1999 /dev/sdc1

SEE ALSO
       lvm(8), vgconvert(8) pvs(8)

Sistina Software UK             LVM TOOLS 2.02.133(2) (2015-10-30)                      PVMOVE(8)

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