NAME
pvmove - move physical extents
SYNOPSIS
pvmove [--abort] [--alloc AllocationPolicy] [-b|--background]
[-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
specifed, 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 them at the last
checkpoint.
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).
OPTIONS
--abort
Abort any moves in progress.
--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 logical extents of any logical volumes on /dev/hda4 to free
physical extents elsewhere in the volume group, giving verbose runtime
information, use:
pvmove -v /dev/hda4
SEE ALSO
lvm(8), vgconvert(8)