Provided by: lvm2_2.02.133-1ubuntu10_amd64 
NAME
pvmove — move physical extents
SYNOPSIS
pvmove [--abort] [--alloc AllocationPolicy] [--atomic] [-b|--background] [--commandprofile ProfileName]
[-d|--debug] [-h|--help] [-i|--interval Seconds] [--noudevsync] [-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 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
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-allocated 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
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 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 volumes are removed, leaving behind the segments on the destination physical
volume. 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 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
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)