Provided by: lvm2_2.02.133-1ubuntu10_amd64 bug

NAME

       lvcreate - create a logical volume in an existing volume group

SYNOPSIS

       lvcreate [-a|--activate [a][e|l|s]{y|n}] [--addtag Tag] [--alloc
       AllocationPolicy] [-A|--autobackup {y|n}] [-H|--cache] [--cachemode
       {passthrough|writeback|writethrough}] [--cachepolicy policy]
       [--cachepool CachePoolLogicalVolume] [--cachesettings key=value]
       [-c|--chunksize ChunkSize] [--commandprofile ProfileName]
       [-C|--contiguous {y|n}] [-d|--debug] [--discards
       {ignore|nopassdown|passdown}] [--errorwhenfull {y|n}] [{-l|--extents
       LogicalExtentsNumber[%{FREE|PVS|VG}] | -L|--size LogicalVolumeSize}
       [-i|--stripes Stripes [-I|--stripesize StripeSize]]] [-h|-?|--help]
       [-K|--ignoreactivationskip] [--ignoremonitoring] [--minor minor
       [-j|--major major]] [--metadataprofile ProfileName] [-m|--mirrors
       Mirrors [--corelog|--mirrorlog {disk|core|mirrored}] [--nosync]
       [-R|--regionsize MirrorLogRegionSize]] [--monitor {y|n}] [-n|--name
       LogicalVolume] [--noudevsync] [-p|--permission {r|rw}] [-M|--persistent
       {y|n}] [--poolmetadatasize MetadataVolumeSize] [--poolmetadataspare
       {y|n}] [--[raid]maxrecoveryrate Rate] [--[raid]minrecoveryrate Rate]
       [-r|--readahead {ReadAheadSectors|auto|none}] [-k|--setactivationskip
       {y|n}] [-s|--snapshot] [-V|--virtualsize VirtualSize] [-t|--test]
       [-T|--thin] [--thinpool ThinPoolLogicalVolume] [--type SegmentType]
       [-v|--verbose] [-W|--wipesignatures {y|n}] [-Z|--zero {y|n}]
       [VolumeGroup[/{ExternalOrigin|Origin|Pool}LogicalVolumeName
       [PhysicalVolumePath[:PE[-PE]]...]]

       lvcreate [-l|--extents LogicalExtentsNumber[%{FREE|ORIGIN|PVS|VG}] |
       -L|--size LogicalVolumeSize] [-c|--chunksize ChunkSize]
       [--commandprofile ProfileName] [--noudevsync] [--ignoremonitoring]
       [--metadataprofile ProfileName] [--monitor {y|n}] [-n|--name
       SnapshotLogicalVolume] -s|--snapshot|-H|--cache
       {[VolumeGroup/]OriginalLogicalVolume [-V|--virtualsize VirtualSize]}

DESCRIPTION

       lvcreate   creates  a  new  logical  volume  in  a  volume  group  (see
       vgcreate(8), vgchange(8)) by allocating logical extents from  the  free
       physical  extent  pool  of  that volume group.  If there are not enough
       free physical extents then  the  volume  group  can  be  extended  (see
       vgextend(8))  with  other  physical  volumes  or  by  reducing existing
       logical volumes of this volume group in size (see lvreduce(8)).  If you
       specify  one  or  more  PhysicalVolumes, allocation of physical extents
       will be restricted to these volumes.
       The second form supports the creation of snapshot logical volumes which
       keep the contents of the original logical volume for backup purposes.

OPTIONS

       See lvm(8) for common options.

       -a|--activate [a][l|e|s]{y|n}
              Controls  the  availability of the Logical Volumes for immediate
              use after the command finishes running.  By default, new Logical
              Volumes are activated (-ay).  If it is possible technically, -an
              will leave the new Logical Volume  inactive.  But  for  example,
              snapshots  of  active  origin  can only be created in the active
              state so -an cannot be used with --type snapshot. This does  not
              apply  to  thin  volume  snapshots, which are by default created
              with flag to skip their activation (-ky).  Normally the --zero n
              argument  has  to  be  supplied too because zeroing (the default
              behaviour) also requires activation.  If  autoactivation  option
              is  used  (-aay),  the  logical  volume  is activated only if it
              matches an item  in  the  activation/auto_activation_volume_list
              set in lvm.conf(5).  For autoactivated logical volumes, --zero n
              and --wipesignatures  n  is  always  assumed  and  it  can't  be
              overridden.  If  the  clustered  locking  is  enabled, -aey will
              activate exclusively on one node and -a{a|l}y will activate only
              on the local node.

       -H|--cache
              Creates  cache  or  cache  pool  logical volume.  Specifying the
              optional argument --extents or --size will cause the creation of
              the  cache  logical  volume.   When  the  Volume  group  name is
              specified together with existing logical volume  name  which  is
              NOT  a  cache  pool name, such volume is treated as cache origin
              volume and cache pool is created. In this case the --extents  or
              --size  is  used  to  specify  size  of  cache pool volume.  See
              lvmcache(7) for more info about caching support.  Note that  the
              cache  segment  type  requires  a dm-cache kernel module version
              1.3.0 or greater.

       --cachemode {passthrough|writeback|writethrough}
              Specifying a cache mode determines when the writes to a cache LV
              are  considered  complete.  When writeback is specified, a write
              is considered complete as soon as it is stored in the cache pool
              LV.  If writethough is specified, a write is considered complete
              only when it has been stored in the cache pool  LV  and  on  the
              origin  LV.   While writethrough may be slower for writes, it is
              more resilient if something should happen to a device associated
              with the cache pool LV.

       --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 CachePoolLogicalVolume{Name|Path}
              Specifies  the  name of cache pool volume name. The other way to
              specify pool name  is  to  append  name  to  Volume  group  name
              argument.

       --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.

       -c|--chunksize ChunkSize[b|B|s|S|k|K|m|M|g|G]
              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 4KiB.
              For cache pools the value must a multiple of 32KiB between 32KiB
              and 1GiB. The default is 64KiB.
              For thin pools the value must be a  multiple  of  64KiB  between
              64KiB and 1GiB.  Default value starts with 64KiB and grows up to
              fit the pool metadata size within 128MiB, if the  pool  metadata
              size    is    not    specified.     See    lvm.conf(5)   setting
              allocation/thin_pool_chunk_size_policy   to   select   different
              calculation policy.  Thin pool target version <1.4 requires this
              value to be a power of 2.  For target version  <1.5  discard  is
              not supported for non power of 2 values.

       -C|--contiguous {y|n}
              Sets  or  resets  the  contiguous  allocation policy for logical
              volumes. Default is no contiguous allocation  based  on  a  next
              free principle.

       --corelog
              This is shortcut for option --mirrorlog core.

       --discards {ignore|nopassdown|passdown}
              Sets discards behavior for thin pool.  Default is passdown.

       --errorwhenfull {y|n}
              Configures  thin  pool  behaviour  when data space is exhausted.
              Default is no.  Device will queue I/O  operations  until  target
              timeout (see dm-thin-pool kernel module option no_space_timeout)
              expires. Thus configured system has a time to  i.e.  extend  the
              size  of  thin  pool  data  device.   When  set  to yes, the I/O
              operation is immeditelly errored.

       -K|--ignoreactivationskip
              Ignore the flag to skip Logical Volumes during activation.   Use
              --setactivationskip  option  to set or reset activation skipping
              flag persistently for logical volume.

       --ignoremonitoring
              Make no attempt to interact with dmeventd  unless  --monitor  is
              specified.

       -l|--extents LogicalExtentsNumber[%{VG|PVS|FREE|ORIGIN}]
              Gives  the  number  of  logical  extents to allocate for the new
              logical volume.  The total number of physical extents  allocated
              will  be  greater  than  this,  for  example,  if  the volume is
              mirrored.  The number can also be expressed as a  percentage  of
              the  total  space  in the Volume Group with the suffix %VG, as a
              percentage of the remaining free space in the Volume Group  with
              the  suffix  %FREE,  as a percentage of the remaining free space
              for the specified PhysicalVolume(s) with  the  suffix  %PVS,  or
              (for  a  snapshot)  as  a  percentage  of the total space in the
              Origin Logical Volume with the suffix %ORIGIN  (i.e.  100%ORIGIN
              provides  space  for  the  whole  origin).   When expressed as a
              percentage, the number is treated as an approximate upper  limit
              for  the  number  of physical extents to be allocated (including
              extents used by any mirrors, for example).

       -j|--major major
              Sets the major number.  Major numbers  are  not  supported  with
              pool  volumes.   This  option is supported only on older systems
              (kernel version 2.4) and is  ignored  on  modern  Linux  systems
              where major numbers are dynamically assigned.

       --metadataprofile ProfileName
              Uses  and  attaches the ProfileName configuration profile to the
              logical  volume  metadata.  Whenever  the  logical   volume   is
              processed  next  time,  the profile is automatically applied. If
              the volume group  has  another  profile  attached,  the  logical
              volume   profile   is   preferred.   See  lvm.conf(5)  for  more
              information about metadata profiles.

       --minor minor
              Sets the minor number.  Minor numbers  are  not  supported  with
              pool volumes.

       -m|--mirrors mirrors
              Creates  a  mirrored  logical  volume  with mirrors copies.  For
              example, specifying -m 1 would result  in  a  mirror  with  two-
              sides; that is, a linear volume plus one copy.

              Specifying   the  optional  argument  --nosync  will  cause  the
              creation of the mirror to skip  the  initial  resynchronization.
              Any  data  written afterwards will be mirrored, but the original
              contents will not be copied.  This  is  useful  for  skipping  a
              potentially long and resource intensive initial sync of an empty
              device.

              There are two implementations of mirroring which can be used and
              correspond  to  the  "raid1"  and  "mirror"  segment types.  The
              default is "raid1".  See the --type option for more  information
              if  you would like to use the legacy "mirror" segment type.  See
              lvm.conf(5)    settings     global/mirror_segtype_default    and
              global/raid10_segtype_default   to   configure   default  mirror
              segment type.  The options --mirrorlog and  --corelog  apply  to
              the legacy "mirror" segment type only.

       --mirrorlog {disk|core|mirrored}
              Specifies  the  type  of  log  to  be  used  for logical volumes
              utilizing the legacy "mirror" segment type.
              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.
              Using core means the mirror is regenerated by copying  the  data
              from the first device each time the logical volume is activated,
              like after every reboot.
              Using mirrored will create  a  persistent  log  that  is  itself
              mirrored.

       --monitor {y|n}
              Starts  or  avoids  monitoring a mirrored, snapshot or thin pool
              logical volume with dmeventd, if it is installed.  If  a  device
              used  by a monitored mirror reports an I/O error, the failure is
              handled according  to  activation/mirror_image_fault_policy  and
              activation/mirror_log_fault_policy set in lvm.conf(5).

       -n|--name LogicalVolume{Name|Path}
              Sets the name for the new logical volume.
              Without  this option a default name of "lvol#" will be generated
              where # is the LVM internal number of the logical volume.

       --nosync
              Causes  the  creation  of  the  mirror  to  skip   the   initial
              resynchronization.

       --noudevsync
              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.

       -p|--permission {r|rw}
              Sets access permissions to read only (r) or read and write (rw).
              Default is read and write.

       -M|--persistent {y|n}
              Set  to  y  to make the minor number specified persistent.  Pool
              volumes  cannot  have  persistent  major  and   minor   numbers.
              Defaults  to  yes  only when major or minor number is specified.
              Otherwise it is no.

       --poolmetadatasize MetadataVolumeSize[b|B|s|S|k|K|m|M|g|G]
              Sets the size of  pool's  metadata  logical  volume.   Supported
              values  are  in  range between 2MiB and 16GiB for thin pool, and
              upto 16GiB for cache pool. The minimum value  is  computed  from
              pool's  data size.  Default value for thin pool is (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.

       --[raid]maxrecoveryrate Rate[b|B|s|S|k|K|m|M|g|G]
              Sets  the maximum recovery rate for a RAID logical volume.  Rate
              is specified as an amount per second  for  each  device  in  the
              array.   If  no suffix is given, then KiB/sec/device is assumed.
              Setting the recovery rate to 0 means it will be unbounded.

       --[raid]minrecoveryrate Rate[b|B|s|S|k|K|m|M|g|G]
              Sets the minimum recovery rate for a RAID logical volume.   Rate
              is  specified  as  an  amount  per second for each device in the
              array.  If no suffix is given, then KiB/sec/device  is  assumed.
              Setting the recovery rate to 0 means it will be unbounded.

       -r|--readahead {ReadAheadSectors|auto|none}
              Sets read ahead sector count of this logical volume.  For volume
              groups with metadata in  lvm1  format,  this  must  be  a  value
              between  2  and 120.  The default value is auto which allows the
              kernel to  choose  a  suitable  value  automatically.   none  is
              equivalent to specifying zero.

       -R|--regionsize MirrorLogRegionSize[b|B|s|S|k|K|m|M|g|G]
              A  mirror is divided into regions of this size (in MiB), and the
              mirror log uses this granularity to track which regions  are  in
              sync.

       -k|--setactivationskip {y|n}
              Controls  whether Logical Volumes are persistently flagged to be
              skipped during activation. By default, thin snapshot volumes are
              flagged     for     activation     skip.      See    lvm.conf(5)
              activation/auto_set_activation_skip how to  change  its  default
              behaviour.     To    activate    such    volumes,    an    extra
              --ignoreactivationskip option must be  used.  The  flag  is  not
              applied  during  deactivation.  Use lvchange --setactivationskip
              command to change the skip flag for existing  volumes.   To  see
              whether the flag is attached, use lvs command where the state of
              the flag is reported within lv_attr bits.

       -L|--size LogicalVolumeSize[b|B|s|S|k|K|m|M|g|G|t|T|p|P|e|E]
              Gives the size to allocate for the new logical volume.   A  size
              suffix  of  B  for  bytes,  S  for  sectors  as 512 bytes, K for
              kilobytes, M for megabytes, G for gigabytes, T for terabytes,  P
              for petabytes or E for exabytes is optional.
              Default unit is megabytes.

       -s|--snapshot OriginalLogicalVolume{Name|Path}
              Creates a snapshot logical volume (or snapshot) for an existing,
              so  called  original  logical  volume  (or  origin).   Snapshots
              provide a 'frozen image' of the contents of the origin while the
              origin can still be updated. They enable consistent backups  and
              online recovery of removed/overwritten data/files.
              Thin  snapshot  is  created when the origin is a thin volume and
              the size IS NOT specified.  Thin  snapshot  shares  same  blocks
              within  the thin pool volume.  The non thin volume snapshot with
              the specified size does not need the same amount of storage  the
              origin  has.  In  a typical scenario, 15-20% might be enough. In
              case the snapshot runs out of storage, use lvextend(8)  to  grow
              it.  Shrinking  a  snapshot is supported by lvreduce(8) as well.
              Run lvs(8) on the snapshot in order to check how  much  data  is
              allocated to it.  Note: a small amount of the space you allocate
              to the snapshot is used to track the locations of the chunks  of
              data,  so  you  should  allocate  slightly  more  space than you
              actually need and monitor (--monitor)  the  rate  at  which  the
              snapshot  data is growing so you can avoid running out of space.
              If --thinpool is specified, thin volume is created that will use
              given  original logical volume as an external origin that serves
              unprovisioned blocks.  Only read-only volumes  can  be  used  as
              external  origins.   To  make  the  volume  external origin, lvm
              expects the volume to be inactive.  External origin  volume  can
              be  used/shared  for  many thin volumes even from different thin
              pools. See lvconvert(8) for online conversion  to  thin  volumes
              with external origin.

       -i|--stripes Stripes
              Gives  the  number  of  stripes.  This is equal to the number of
              physical volumes to scatter the logical volume.  When creating a
              RAID 4/5/6 logical volume, the extra devices which are necessary
              for parity are internally accounted for.  Specifying -i 3  would
              use  3  devices  for striped logical volumes, 4 devices for RAID
              4/5, and 5 devices for RAID 6.  Alternatively, RAID  4/5/6  will
              stripe  across  all  PVs  in  the volume group or all of the PVs
              specified if the -i argument is omitted.

       -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
              Creates  thin  pool  or thin logical volume or both.  Specifying
              the  optional  argument  --size  or  --extents  will  cause  the
              creation  of  the  thin  pool  logical  volume.   Specifying the
              optional argument --virtualsize will cause the creation  of  the
              thin  logical  volume  from  given thin pool volume.  Specifying
              both arguments will cause the creation of  both  thin  pool  and
              thin volume using this pool.  See lvmthin(7) for more info about
              thin provisioning support.  Thin  provisioning  requires  device
              mapper kernel driver from kernel 3.2 or greater.

       --thinpool ThinPoolLogicalVolume{Name|Path}
              Specifies  the  name  of thin pool volume name. The other way to
              specify pool name  is  to  append  name  to  Volume  group  name
              argument.

       --type SegmentType
              Creates  a  logical  volume  with  the  specified  segment type.
              Supported types are: cache, cache-pool, error,  linear,  mirror,
              raid1,  raid4, raid5_la, raid5_ls (= raid5), raid5_ra, raid5_rs,
              raid6_nc,  raid6_nr,  raid6_zr  (=  raid6),  raid10,   snapshot,
              striped,  thin,  thin-pool  or  zero.   Segment  type may have a
              commandline switch alias that will enable  its  use.   When  the
              type  is  not  explicitly specified an implicit type is selected
              from combination of options:  -H|--cache|--cachepool  (cache  or
              cachepool),    -T|--thin|--thinpool    (thin    or    thinpool),
              -m|--mirrors (raid1 or  mirror),  -s|--snapshot|-V|--virtualsize
              (snapshot  or  thin),  -i|--stripes  (striped).  Default segment
              type is linear.

       -V|--virtualsize VirtualSize[b|B|s|S|k|K|m|M|g|G|t|T|p|P|e|E]
              Creates a thinly provisioned device or a sparse  device  of  the
              given  size  (in  MiB  by  default).   See  lvm.conf(5) settings
              global/sparse_segtype_default  to   configure   default   sparse
              segment   type.    See  lvmthin(7)  for  more  info  about  thin
              provisioning support.  Anything written  to  a  sparse  snapshot
              will be returned when reading from it.  Reading from other areas
              of the device will return blocks  of  zeros.   Virtual  snapshot
              (sparse  snapshot)  is  implemented by creating a hidden virtual
              device of the requested size using the zero target.  A suffix of
              _vorigin  is used for this device.  Note: using sparse snapshots
              is  not  efficient  for  larger   device   sizes   (GiB),   thin
              provisioning should be used for this case.

       -W|--wipesignatures {y|n}
              Controls  wiping of detected signatures on newly created Logical
              Volume.  If this  option  is  not  specified,  then  by  default
              signature  wiping is done each time the zeroing ( -Z|--zero ) is
              done.   This   default   behaviour   can   be   controlled    by
              allocation/wipe_signatures_when_zeroing_new_lvs setting found in
              lvm.conf(5).
              If blkid wiping is used allocation/use_blkid_wiping  setting  in
              lvm.conf(5))  and  LVM2  is  compiled with blkid wiping support,
              then blkid(8) library is used  to  detect  the  signatures  (use
              blkid  -k  command  to list the signatures that are recognized).
              Otherwise, native LVM2 code is used  to  detect  signatures  (MD
              RAID, swap and LUKS signatures are detected only in this case).
              Logical volume is not wiped if the read only flag is set.

       -Z|--zero {y|n}
              Controls  zeroing  of  the first 4KiB of data in the new logical
              volume.  Default  is  yes.   Snapshot  COW  volumes  are  always
              zeroed.   Logical  volume is not zeroed if the read only flag is
              set.
              Warning: trying to mount an unzeroed logical  volume  can  cause
              the system to hang.

Examples

       Creates  a striped logical volume with 3 stripes, a stripe size of 8KiB
       and a size of 100MiB in the  volume  group  named  vg00.   The  logical
       volume name will be chosen by lvcreate:

       lvcreate -i 3 -I 8 -L 100M vg00

       Creates a mirror logical volume with 2 sides with a useable size of 500
       MiB.  This  operation  would  require  3  devices  (or  option  --alloc
       anywhere) - two for the mirror devices and one for the disk log:

       lvcreate -m1 -L 500M vg00

       Creates a mirror logical volume with 2 sides with a useable size of 500
       MiB.  This operation would require 2 devices - the log is "in-memory":

       lvcreate -m1 --mirrorlog core -L 500M vg00

       Creates a snapshot logical volume named "vg00/snap" which has access to
       the  contents  of  the  original  logical  volume named "vg00/lvol1" at
       snapshot logical volume creation time. If the original  logical  volume
       contains a file system, you can mount the snapshot logical volume on an
       arbitrary directory in order to access the contents of  the  filesystem
       to run a backup while the original filesystem continues to get updated:

       lvcreate --size 100m --snapshot --name snap /dev/vg00/lvol1

       Creates  a  snapshot  logical  volume  named  "vg00/snap" with size for
       overwriting 20% of the original logical volume named "vg00/lvol1".:

       lvcreate -s -l 20%ORIGIN --name snap vg00/lvol1

       Creates a sparse device named /dev/vg1/sparse of size 1TiB  with  space
       for just under 100MiB of actual data on it:

       lvcreate --virtualsize 1T --size 100M --snapshot --name sparse vg1

       Creates  a  linear  logical  volume "vg00/lvol1" using physical extents
       /dev/sda:0-7 and /dev/sdb:0-7 for allocation of extents:

       lvcreate -L 64M -n lvol1 vg00 /dev/sda:0-7 /dev/sdb:0-7

       Creates a 5GiB RAID5 logical volume "vg00/my_lv", with 3 stripes  (plus
       a parity drive for a total of 4 devices) and a stripesize of 64KiB:

       lvcreate --type raid5 -L 5G -i 3 -I 64 -n my_lv vg00

       Creates  a  RAID5  logical  volume  "vg00/my_lv", using all of the free
       space in the VG and spanning all the PVs in the VG:

       lvcreate --type raid5 -l 100%FREE -n my_lv vg00

       Creates a 5GiB RAID10 logical volume "vg00/my_lv", with 2 stripes on  2
       2-way  mirrors.   Note that the -i and -m arguments behave differently.
       The -i specifies the number of stripes.  The -m specifies the number of
       additional copies:

       lvcreate --type raid10 -L 5G -i 2 -m 1 -n my_lv vg00

       Creates  100MiB  pool logical volume for thin provisioning build with 2
       stripes 64KiB and chunk size 256KiB together with 1TiB thin provisioned
       logical volume "vg00/thin_lv":

       lvcreate -i 2 -I 64 -c 256 -L100M -T vg00/pool -V 1T --name thin_lv

       Creates a thin snapshot volume "thinsnap" of thin volume "thinvol" that
       will share the same blocks within the thin pool.  Note: the  size  MUST
       NOT be specified, otherwise the non-thin snapshot is created instead:

       lvcreate -s vg00/thinvol --name thinsnap

       Creates  a  thin  snapshot volume of read-only inactive volume "origin"
       which then becomes the thin  external  origin  for  the  thin  snapshot
       volume in vg00 that will use an existing thin pool "vg00/pool":

       lvcreate -s --thinpool vg00/pool origin

       Create  a  cache  pool  LV  that can later be used to cache one logical
       volume.

       lvcreate --type cache-pool -L 1G -n my_lv_cachepool vg /dev/fast1

       If there is an existing cache pool LV, create  the  large  slow  device
       (i.e.  the  origin  LV)  and  link  it  to  the supplied cache pool LV,
       creating a cache LV.

       lvcreate --cache -L 100G -n my_lv vg/my_lv_cachepool /dev/slow1

       If there is an existing logical volume, create the small and fast cache
       pool  LV  and link it to the supplied existing logical volume (i.e. the
       origin LV), creating a cache LV.

       lvcreate --type cache -L 1G -n my_lv_cachepool vg/my_lv /dev/fast1

SEE ALSO

       lvm(8),    lvm.conf(5),    lvmcache(7),    lvmthin(7),    lvconvert(8),
       lvchange(8), lvextend(8), lvreduce(8), lvremove(8), lvrename(8) lvs(8),
       lvscan(8), vgcreate(8), blkid(8)