.TH PVMOVE 8 "LVM TOOLS #VERSION#" "Sistina Software UK" \" -*- nroff -*-
.SH NAME
pvmove \- move physical extents
.SH SYNOPSIS
.B pvmove
[\-\-abort]
[\-\-alloc AllocationPolicy]
[\-b|\-\-background]
[\-d|\-\-debug] [\-h|\-\-help] [\-i|\-\-interval Seconds] [\-v|\-\-verbose]
[\-n|\-\-name LogicalVolume] 
[SourcePhysicalVolume[:PE[-PE]...] [DestinationPhysicalVolume[:PE[-PE]...]...]]
.SH DESCRIPTION
.B pvmove
allows you to move the allocated physical extents (PEs) on
.I SourcePhysicalVolume
to one or more other physical volumes (PVs).
You can optionally specify a source
.I LogicalVolume
in which case only extents used by that LV will be moved to 
free (or specified) extents on
.IR DestinationPhysicalVolume (s).
If no
.I DestinationPhysicalVolume
is specifed, the normal allocation rules for the volume group are used.

If \fBpvmove\fP gets interrupted for any reason (e.g. the machine crashes)
then run \fBpvmove\fP again without any PhysicalVolume arguments to
restart any moves that were in progress from the last checkpoint.
Alternatively use \fBpvmove --abort\fP 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.

\fBpvmove\fP 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 \fBvgconvert\fP(8).

.SH OPTIONS
.TP
.I \-\-abort
Abort any moves in progress.
.TP
.I \-b, \-\-background
Run the daemon in the background.
.TP
.I \-i, \-\-interval Seconds
Report progress as a percentage at regular intervals.
.TP
.I \-n, \-\-name " \fILogicalVolume\fR"
Move only the extents belonging to
.I LogicalVolume
from
.I SourcePhysicalVolume
instead of all allocated extents to the destination physical volume(s).

.SH EXAMPLES
To move all logical extents of any logical volumes on
.B /dev/hda4
to free physical extents elsewhere in the volume group, giving verbose
runtime information, use:
.sp
\	pvmove -v /dev/hda4
.sp
.SH SEE ALSO
.BR lvm (8),
.BR vgconvert (8)