NAME
lvconvert - convert a logical volume from linear to mirror or snapshot
SYNOPSIS
lvconvert -m|--mirrors Mirrors [--mirrorlog {disk|core}] [--corelog]
[-R|--regionsize MirrorLogRegionSize] [-A|--alloc AllocationPolicy]
[-b|--background] [-f|--force] [-i|--interval Seconds] [-h|-?|--help]
[--noudevsync] [-v|--verbose] [-y|--yes] [--version]
LogicalVolume[Path] [PhysicalVolume[Path][:PE[-PE]]...]
lvconvert -s|--snapshot [-c|--chunksize ChunkSize] [-h|-?|--help]
[--noudevsync] [-v|--verbose] [-Z|--zero y|n] [--version]
OriginalLogicalVolume[Path] SnapshotLogicalVolume[Path]
lvconvert --repair [-h|-?|--help] [-v|--verbose] [--version]
LogicalVolume[Path] [PhysicalVolume[Path]...]
DESCRIPTION
lvconvert will change a linear logical volume to a mirror logical
volume or to a snapshot of linear volume and vice versa. It is also
used to add and remove disk logs from mirror devices.
If the conversion requires allocation of physical extents (for example,
when converting from linear to mirror) and you specify one or more
PhysicalVolumes (optionally with ranges of physical extents),
allocation of physical extents will be restricted to these physical
extents. If the conversion frees physical extents (for example, when
converting from a mirror to a linear, or reducing mirror legs) and you
specify one or more PhysicalVolumes, the freed extents come first from
the specified PhysicalVolumes.
OPTIONS
See lvm for common options.
Exactly one of --mirrors, --repair or --snapshot arguments required.
-m, --mirrors Mirrors
Specifies the degree of the mirror you wish to create. For
example, "-m 1" would convert the original logical volume to a
mirror volume with 2-sides; that is, a linear volume plus one
copy.
--mirrorlog {disk|core}
Specifies the type of log to use. The default is disk, which is
persistent and requires a small amount of storage space, usually
on a separate device from the data being mirrored. Core may be
useful for short-lived mirrors: It means the mirror is
regenerated by copying the data from the first device again
every time the device is activated - perhaps, for example, after
every reboot.
--corelog
The optional argument "--corelog" is the same as specifying
"--mirrorlog core".
-R, --regionsize MirrorLogRegionSize
A mirror is divided into regions of this size (in MB), and the
mirror log uses this granularity to track which regions are in
sync.
-b, --background
Run the daemon in the background.
-i, --interval Seconds
Report progress as a percentage at regular intervals.
--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.
--repair
Repair a mirror after suffering a disk failure. The mirror will
be brought back into a consistent state. By default, the
original number of mirrors will be restored if possible.
Specify -y on the command line to skip the prompts. Use -f if
you do not want any replacement. Additionally, you may use
--use-policies to use the device replacement policy specified in
lvm.conf, viz. activation/mirror_log_fault_policy or
activation/mirror_device_fault_policy.
-s, --snapshot
Create a snapshot from existing logical volume using another
existing logical volume as its origin.
-c, --chunksize ChunkSize
Power of 2 chunk size for the snapshot logical volume between 4k
and 512k.
-Z, --zero y|n
Controls zeroing of the first KB of data in the snapshot. If
the volume is read-only the snapshot will not be zeroed.
Examples
"lvconvert -m1 vg00/lvol1"
converts the linear logical volume "vg00/lvol1" to a two-way mirror
logical volume.
"lvconvert --mirrorlog core vg00/lvol1"
converts a mirror with a disk log to a mirror with an in-memory log.
"lvconvert --mirrorlog disk vg00/lvol1"
converts a mirror with an in-memory log to a mirror with a disk log.
"lvconvert -m0 vg00/lvol1"
converts a mirror logical volume to a linear logical volume.
"lvconvert -s vg00/lvol1 vg00/lvol2"
converts logical volume "vg00/lvol2" to snapshot of original volume
"vg00/lvol1"
"lvconvert -m1 vg00/lvol1 /dev/sda:0-15 /dev/sdb:0-15"
converts linear logical volume "vg00/lvol1" to a two-way mirror, using
physical extents /dev/sda:0-15 and /dev/sdb:0-15 for allocation of new
extents.
"lvconvert -m0 vg00/lvmirror1 /dev/sda
converts mirror logical volume "vg00/lvmirror1" to linear, freeing
physical extents from /dev/sda.
SEE ALSO
lvm(8), vgcreate(8), lvremove(8), lvrename(8), lvextend(8),
lvreduce(8), lvdisplay(8), lvscan(8)