LVCONVERT(8)						      System Manager's Manual						      LVCONVERT(8)

NAME

       lvconvert - convert a logical volume from linear to mirror or snapshot

SYNOPSIS

       lvconvert -m|--mirrors Mirrors [--mirrorlog {disk|core|mirrored}] [--corelog] [-R|--regionsize MirrorLogRegionSize] [-A|--alloc Allocation-
       Policy] [-b|--background] [-f|--force] [-i|--interval Seconds] [-h|-?|--help] [--stripes Stripes  [-I|--stripesize  StripeSize]]  [--noude-
       vsync] [-v|--verbose] [-y|--yes] [--version]
       LogicalVolume[Path] [PhysicalVolume[Path][:PE[-PE]]...]

       lvconvert --splitmirrors Images --name SplitLogicalVolumeName
       MirrorLogicalVolume[Path] [SplittablePhysicalVolume[Path][:PE[-PE]]...]

       lvconvert -s|--snapshot [-c|--chunksize ChunkSize] [-h|-?|--help] [--noudevsync] [-v|--verbose] [-Z|--zero y|n] [--version]
       OriginalLogicalVolume[Path] SnapshotLogicalVolume[Path]

       lvconvert --merge [-b|--background] [-i|--interval Seconds] [-h|-?|--help] [-v|--verbose] [--version] 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 --splitmirrors, --mirrors, --repair, --snapshot or --merge arguments is 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|mirrored}
	      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.   Using
	      "mirrored" will create a persistent log that is itself mirrored.

       --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  cre-
	      ates.

       --splitmirrors Images
	      The  number  of redundant Images of a mirror to be split off and used to form a new logical volume.  A name must be supplied for the
	      newly-split-off logical volume using the --name argument.

       -n Name
	      The name to apply to a logical volume which has been split off from a mirror logical volume.

       -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.

       --merge
	      Merges a snapshot into its origin volume. If both the origin and snapshot volume are not open  the  merge  will  start  immediately.
	      Otherwise,  the merge will start the first time either the origin or snapshot are activated and both are closed.	Merging a snapshot
	      into an origin that cannot be closed, for example a root filesystem, is deferred until the next time the origin volume is activated.
	      When  merging  starts,  the  resulting  logical  volume  will  have the origin's name, minor number and UUID.  While the merge is in
	      progress, reads or writes to the origin appear as they were directed to the snapshot being merged.  When	the  merge  finishes,  the
	      merged  snapshot is removed.  Multiple snapshots may be specified on the commandline or a @tag may be used to specify multiple snap-
	      shots be merged to their respective origin.

       --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.  activa-
	      tion/mirror_log_fault_policy or activation/mirror_device_fault_policy.

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.

       "lvconvert --merge vg00/lvol1_snap"
       merges "vg00/lvol1_snap" into its origin.

       "lvconvert --merge @some_tag"
       If vg00/lvol1, vg00/lvol2, and vg00/lvol3 are all tagged with "some_tag" each snapshot  logical	volume	will  be  merged  serially,  e.g.:
       vg00/lvol1, then vg00/lvol2, then vg00/lvol3.  If --background were used it would start all snapshot logical volume merges in parallel.

SEE ALSO

       lvm(8), vgcreate(8), lvremove(8), lvrename(8), lvextend(8), lvreduce(8), lvdisplay(8), lvscan(8)

Red Hat, Inc						 LVM TOOLS 2.02.67(2) (2010-06-04)					      LVCONVERT(8)