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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] [--reportformat  {basic|json}]  [-v|--verbose]
       [-n|--name LogicalVolume] [SourcePhysicalVolume[:PE[-PE]...]  [DestinationPhysicalVolume[: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 LogicalVolume in which case only extents used  by
       that LV will be moved to free (or specified) extents on DestinationPhysicalVolume(s).  If no DestinationPhysi‐
       calVolume 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  Physi‐
       calVolume  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 SourcePhysicalVolumes,
       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 movements required.

       2.  Every Logical Volume in the Volume Group is searched for contiguous data that need moving 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-allo‐
       cated location.  The original LV is updated to use the new temporary mirror segment in the pvmove  LV  instead
       of accessing 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  tempo‐
       rary 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  con‐
       verted 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 contains 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 vol‐
       umes are removed, leaving behind the segments on the destination physical volume.  If an abort is issued  dur‐
       ing the move, all logical volumes being moved will remain on the source physical volume.

              Make the entire operation atomic.  That is, ensure that all affected logical volumes 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



Sistina Software UK                    LVM TOOLS 2.02.166(2)-RHEL7 (2016-11-16)                             PVMOVE(8)