Provided by: lvm2_2.02.133-1ubuntu10_amd64 bug


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


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

       lvconvert    --split    [--commandprofile   ProfileName]   [-h|-?|--help]   [--noudevsync]
       [-v|--verbose] SplitableLogicalVolume{Name|Path}

       lvconvert    --splitcache|--uncache    [--commandprofile    ProfileName]    [-h|-?|--help]
       [--noudevsync] [-v|--verbose] [--version] CacheLogicalVolume{Name|Path}

       lvconvert   --splitmirrors   Images   [--name   SplitLogicalVolumeName]   [--trackchanges]
       MirrorLogicalVolume[Path]                  [--commandprofile                  ProfileName]

       lvconvert  --splitsnapshot  [--commandprofile  ProfileName]  [-h|-?|--help] [--noudevsync]
       [-v|--verbose] [--version] SnapshotLogicalVolume[Path]

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

       lvconvert --merge [-b|--background] [-i|--interval Seconds] [--commandprofile ProfileName]
       [-h|-?|--help] [-v|--verbose] [--version] LogicalVolume[Path]...

       lvconvert  --repair  [--stripes  Stripes  [-I|--stripesize  StripeSize]] [--commandprofile
       ProfileName]     [-h|-?|--help]     [-v|--verbose]     [--version]     LogicalVolume[Path]

       lvconvert   --replace   PhysicalVolume   [--commandprofile   ProfileName]   [-h|-?|--help]
       [-v|--verbose] [--version] LogicalVolume[Path] [PhysicalVolume[Path]...]

       lvconvert   --type   thin[-pool]|-T|--thin   [--originname    NewExternalOriginVolumeName]
       [--thinpool    ThinPoolLogicalVolume{Name|Path}   [-c|--chunksize   ChunkSize[bBsSkKmMgG]]
       [--discards                 {ignore|nopassdown|passdown}]                  [--poolmetadata
       ThinPoolMetadataLogicalVolume{Name|Path}                |               --poolmetadatasize
       ThinPoolMetadataSize[bBsSkKmMgG]]      [-r|--readahead       {ReadAheadSectors|auto|none}]
       [--stripes Stripes      [-I|--stripesize StripeSize]]]     [--poolmetadataspare     {y|n}]
       [-Z|--zero {y|n}]]   [--commandprofile    ProfileName]    [-h|-?|--help]    [-v|--verbose]
       [--version]  [[ExternalOrigin|ThinPool]LogicalVolume{Name|Path}] [PhysicalVolume[Path][:PE
       [-PE]] ...

       lvconvert --type cache[-pool]|-H|--cache  [--cachepool  CachePoolLogicalVolume{Name|Path}]
       [-c|--chunksize      ChunkSize[bBsSkKmMgG]]     [--cachemode     {writeback|writethrough}]
       [--cachepolicy       policy]       [--cachesettings       key=value]       [--poolmetadata
       CachePoolMetadataLogicalVolume{Name|Path}               |               --poolmetadatasize
       CachePoolMetadataSize[bBsSkKmMgG]]    [--poolmetadataspare    {y|n}]     [--commandprofile
       ProfileName]    [-h|-?|--help]    [-v|--verbose]    [--version]   LogicalVolume{Name|Path}


       lvconvert is used to change the segment type (i.e. linear, mirror, etc) or characteristics
       of  a logical volume.  For example, it can add or remove the redundant images of a logical
       volume, change the log type of a mirror, or designate  a  logical  volume  as  a  snapshot
       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.


       See lvm(8) for common options.
       Exactly one of --cache, --corelog, --merge, --mirrorlog, --mirrors,  --repair,  --replace,
       --snapshot,  --split,  --splitcache,  --splitsnapshot,  --splitmirrors,  --thin, --type or
       --uncache arguments is required.

       -b, --background
              Run the daemon in the background.

       -H, --cache, --type cache
              Converts logical volume to a cached LV with the use of cache  pool  specified  with
              --cachepool.    For  more  information  on  cache  pool  LVs  and  cache  LVs,  see

       --cachepolicy policy
              Only applicable to cached LVs; see also lvmcache(7). Sets the cache policy.  mq  is
              the basic policy name. smq is more advanced version available in newer kernels.

       --cachepool CachePoolLV
              This  argument  is  necessary  when converting a logical volume to a cache LV.  For
              more information on cache pool LVs and cache LVs, see lvmcache(7).

       --cachesettings key=value
              Only applicable to cached  LVs;  see  also  lvmcache(7).  Sets  the  cache  tunable
              settings.  In  most  use-cases,  default values should be adequate.  Special string
              value default switches setting back to its default kernel value and removes it from
              the list of settings stored in lvm2 metadata.

       -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.   There are two implementations of mirroring which
              correspond to the "raid1"  and  "mirror"  segment  types.   The  default  mirroring
              segment  type  is  "raid1".   If  the  legacy "mirror" segment type is desired, the
              --type  argument  must  be  used  to  explicitly  select  the  desired  type.   The
              --mirrorlog  and  --corelog  options below are only relevant to the legacy "mirror"
              segment type.

       --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.

              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.

       --type SegmentType
              Used to convert a logical volume to another segment type, like  cache,  cache-pool,
              raid1,  snapshot,  thin, or thin-pool.  When converting a logical volume to a cache
              LV, the --cachepool argument is required.  When converting a logical  volume  to  a
              thin  LV, the --thinpool argument is required.  See lvmcache(7) for more info about
              caching support and lvmthin(7) for thin provisioning support.

       -i, --interval Seconds
              Report progress as a percentage at regular intervals.

              Disables 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.

       --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, unless the --trackchanges argument is given.

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

              Used with --splitmirrors on a raid1 device, this tracks changes so that  the  read-
              only  detached image can be merged efficiently back into the mirror later. Only the
              regions of the detached device where the data changed get resynchronized.

              Please note that this feature is  only  supported  with  the  new  md-based  mirror
              implementation and not with the original device-mapper mirror implementation.

              Separates  SplitableLogicalVolume.  Option is agregating various split commands and
              tries to detect necessary split operation from its arguments.

              Separates CacheLogicalVolume from cache pool.  Before the  logical  volume  becomes
              uncached, cache is flushed.  The cache pool volume is then left unused and could be
              used e.g. for caching another volume.  See also the option --uncache for  uncaching
              and removing cache pool with one command.

              Separates  SnapshotLogicalVolume  from  its  origin.   The volume that is split off
              contains the chunks that differ from the origin along with the metadata  describing
              them.   This  volume can be wiped and then destroyed with lvremove.  The inverse of

       -s, --snapshot, --type snapshot
              Recreates a snapshot from constituent logical volumes (or  copies  of  them)  after
              having  been  separated  using  --splitsnapshot.   For  this  to work correctly, no
              changes may be made to the contents of either volume after the split.

       -c, --chunksize ChunkSize[bBsSkKmMgG]
              Gives the size of chunk for snapshot, cache pool and  thin  pool  logical  volumes.
              Default unit is in kilobytes.

              For  snapshots the value must be power of 2 between 4KiB and 512KiB and the default
              value is 4.

              For cache pools the value must be between 32KiB and 1GiB and the default  value  is

              For  thin  pools  the  value  must  be between 64KiB and 1GiB and the default value
              starts with 64 and scales up to fit the pool metadata size within  128MiB,  if  the
              pool  metadata  size  is  not  specified.   The  value must be a multiple of 64KiB.
              (Early kernel support until thin target version 1.4 required  the  value  to  be  a
              power of 2.  Discards weren't supported for non-power of 2 values until thin target
              version 1.5.)

       --discards {ignore|nopassdown|passdown}
              Specifies whether or not discards will be processed by the thin layer in the kernel
              and  passed  down to the Physical Volume.  Options is currently supported only with
              thin pools.  Default is passdown.

       -Z, --zero {y|n}
              Controls zeroing of the first 4KiB of data in the snapshot.  If the volume is read-
              only the snapshot will not be zeroed.  For thin pool volumes it controls zeroing of
              provisioned blocks.  Note: Provisioning of large zeroed chunks  negatively  impacts

              Merges  a  snapshot  into  its  origin volume or merges a raid1 image that has been
              split from its mirror with --trackchanges back into its mirror.

              To check if your kernel supports the snapshot merge feature,  look  for  'snapshot-
              merge'  in  the  output of dmsetup targets.  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 snapshots  be  merged  to
              their respective origin.

       --originname NewExternalOriginVolumeName
              The  new name for original logical volume, which becomes external origin volume for
              a thin logical volume that will use given --thinpool.
              Without this option a default name of "lvol<n>" will be generated where <n> is  the
              LVM  internal  number  of  the  logical  volume.  This volume will be read-only and
              cannot be further modified as long, as it is being used as the external origin.

       --poolmetadata PoolMetadataLogicalVolume{Name|Path}
              Specifies cache or thin pool metadata  logical  volume.   The  size  should  be  in
              between 2MiB and 16GiB.  Cache pool is specified with the option --cachepool.  Thin
              pool is specified with the option --thinpool.   When  the  specified  pool  already
              exists,  the  pool's  metadata  volume  will  be  swapped  with the given LV.  Pool
              properties (like chunk size, discards or zero) are preserved  by  default  in  this
              case.   It  can be useful for pool metadata repair or its offline resize, since the
              metadata volume is available as regular volume for a user  with  thin  provisioning
              tools     cache_dump(8),     cache_repair(8),    cache_restore(8),    thin_dump(8),
              thin_repair(8) and thin_restore(8).

       --poolmetadatasize PoolMetadataSize[bBsSkKmMgG]
              Sets the size of cache or thin pool's metadata logical volume, if the pool metadata
              volume  is undefined.  Pool is specified with the option --cachepool or --thinpool.
              For thin pool supported value is in the range between 2MiB and 16GiB.  The  default
              value  is  estimated  with  this formula (Pool_LV_size / Pool_LV_chunk_size * 64b).
              Default unit is megabytes.

       --poolmetadataspare {y|n}
              Controls creation and maintanence of pool metadata spare logical volume  that  will
              be  used  for automated pool recovery.  Only one such volume is maintained within a
              volume group with the size of the biggest pool metadata volume.  Default is yes.

       -r, --readahead {ReadAheadSectors|auto|none}
              Sets read ahead sector count of thin pool metadata  logical  volume.   The  default
              value  is  "auto" which allows the kernel to choose a suitable value automatically.
              "None" is equivalent to specifying zero.

              Repair a mirror after suffering a disk failure or try to fix thin pool metadata.

              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(5),
              viz. activation/mirror_log_fault_policy or activation/mirror_device_fault_policy.

              Thin pool repair automates the use of thin_repair(8) tool.  Only inactive thin pool
              volumes  can  be  repaired.   There is no validation of metadata between kernel and
              lvm2.  This requires  further  manual  work.   After  successfull  repair  the  old
              unmodified metadata are still available in "<pool>_meta<n>" LV.

       --replace PhysicalVolume
              Remove  the  specified  device  (PhysicalVolume)  and  replace  it with one that is
              available in the volume group or from the specific list provided.  This  option  is
              only available to RAID segment types (e.g.  raid1, raid5, etc).

       --stripes Stripes
              Gives  the  number  of stripes.  This is equal to the number of physical volumes to
              scatter the logical volume. This does not apply to existing allocated  space,  only
              newly allocated space can be striped.

       -I, --stripesize StripeSize
              Gives the number of kilobytes for the granularity of the stripes.
              StripeSize  must  be 2^n (n = 2 to 9) for metadata in LVM1 format.  For metadata in
              LVM2 format, the stripe size may be a larger power of 2 but  must  not  exceed  the
              physical extent size.

       -T, --thin, --type thin
              Converts  the  logical volume into a thin logical volume of the thin pool specified
              with --thinpool. The original logical volume ExternalOriginLogicalVolume is renamed
              into  a new read-only logical volume.  For the non-default name for this volume use
              --originname.  The volume cannot be further modified as long as it is  used  as  an
              external origin volume for unprovisioned areas of any thin logical volume.

       --thinpool ThinPoolLogicalVolume{Name|Path}
              Specifies  or  converts  logical volume into a thin pool's data volume.  Content of
              converted volume is lost.  Thin pool's metadata logical  volume  can  be  specified
              with   the   option  --poolmetadata  or  allocated  with  --poolmetadatasize.   See
              lvmthin(7) for more info about thin provisioning support.

              Uncaches CacheLogicalVolume.  Before the volume becomes uncached, cache is flushed.
              Unlike  with  --splitcache  the cache pool volume is removed.  This option could be
              seen as an inverse of --cache.


       Converts the linear logical volume "vg00/lvol1" to a two-way mirror logical volume:

       lvconvert -m1 vg00/lvol1

       Converts the linear logical volume "vg00/lvol1" to a two-way RAID1 logical volume:

       lvconvert --type raid1 -m1 vg00/lvol1

       Converts a mirror with a disk log to a mirror with an in-memory log:

       lvconvert --mirrorlog core vg00/lvol1

       Converts a mirror with an in-memory log to a mirror with a disk log:

       lvconvert --mirrorlog disk vg00/lvol1

       Converts a mirror logical volume to a linear logical volume:

       lvconvert -m0 vg00/lvol1

       Converts a mirror logical volume to a RAID1 logical volume with the same number of images:

       lvconvert --type raid1 vg00/mirror_lv

       Converts logical volume "vg00/lvol2" to snapshot of original volume "vg00/lvol1":

       lvconvert -s vg00/lvol1 vg00/lvol2

       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 -m1 vg00/lvol1 /dev/sda:0-15 /dev/sdb:0-15

       Converts  mirror  logical volume "vg00/lvmirror1" to linear, freeing physical extents from

       lvconvert -m0 vg00/lvmirror1 /dev/sda

       Merges "vg00/lvol1_snap" into its origin:

       lvconvert --merge vg00/lvol1_snap

       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.

       lvconvert --merge @some_tag

       Extracts  one image from the mirror, making it a new logical volume named "lv_split".  The
       mirror the image is extracted from is reduced accordingly.   If  it  was  a  2-way  mirror
       (created with '-m 1'), then the resulting original volume will be linear.

       lvconvert --splitmirrors 1 --name lv_split vg00/lvmirror1

       A  mirrored  logical  volume created with --type raid1 can use the --trackchanges argument
       when splitting off an image.  Detach one image from the mirrored logical  volume  lv_raid1
       as  a  separate  read-only  device  and  track  the changes made to the mirror while it is
       detached.  The split-off device has a name of the form lv_raid1_rimage_N,  where  N  is  a
       number, and it cannot be renamed.

       lvconvert --splitmirrors 1 --trackchanges vg00/lv_raid1

       Merge  an  image  that  was  detached  temporarily from its mirror with the --trackchanges
       argument back into its original mirror and bring its contents back up-to-date.

       lvconvert --merge vg00/lv_raid1_rimage_1

       Replaces the physical volume "/dev/sdb1" in the RAID1 logical volume "my_raid1"  with  the
       specified  physical  volume  "/dev/sdf1".   Had  the  argument  "/dev/sdf1" been left out,
       lvconvert would attempt to find a suitable device  from  those  available  in  the  volume

       lvconvert --replace /dev/sdb1 vg00/my_raid1 /dev/sdf1

       Convert  the  logical  volume  "vg00/lvpool"  into  a thin pool with chunk size 128KiB and
       convert "vg00/lv1" into a thin volume using this pool. Original "vg00/lv1" is used  as  an
       external   read-only   origin,  where  all  writes  to  such  volume  are  stored  in  the

       lvconvert --type thin --thinpool vg00/lvpool -c 128 lv1

       Convert  the  logical  volume  "vg00/origin"  into  a  thin  volume  from  the  thin  pool
       "vg00/lvpool".  This  thin  volume will use "vg00/origin" as an external origin volume for
       unprovisioned areas in this volume.  For the read-only external origin use  the  new  name

       lvconvert -T --thinpool vg00/lvpool --originname external vg00/origin

       Convert an existing logical volume to a cache pool LV using the given cache metadata LV.

       lvconvert --type cache-pool --poolmetadata vg00/lvx_meta vg00/lvx_data
       lvrename vg00/lvx_data vg00/lvx_cachepool

       Convert  an  existing logical volume to a cache LV using the given cache pool LV and chunk
       size 128KiB.

       lvconvert --cache --cachepool vg00/lvx_cachepool -c 128 vg00/lvx

       Detach cache pool from an existing cached logical volume "vg00/lvol1" and leave cache pool

       lvconvert --splitcache vg00/lvol1

       Drop cache pool from an existing cached logical volume "vg00/lvol1".

       lvconvert --uncache vg00/lvol1


       lvm(8),  lvm.conf(5),  lvmcache(7),  lvmthin(7),  lvdisplay(8),  lvextend(8), lvreduce(8),
       lvremove(8),  lvrename(8),   lvscan(8),   vgcreate(8),   cache_dump(8),   cache_repair(8),
       cache_restore(8), thin_dump(8), thin_repair(8), thin_restore(8)