NAME
pvmove - move physical extents
SYNOPSIS
pvmove [--abort] [--alloc AllocationPolicy] [-b|--background]
[-d|--debug] [-h|--help] [-i|--interval Seconds] [-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 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.
- -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)