LVM实践

[root@ftp:/root]
> fdisk -l

Disk /dev/sda: 53.7 GB, 53687091200 bytes, 104857600 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk label type: dos
Disk identifier: 0x000c50af

   Device Boot      Start         End      Blocks   Id  System
/dev/sda1   *        2048     2099199     1048576   83  Linux
/dev/sda2         2099200   104857599    51379200   8e  Linux LVM

Disk /dev/sdb: 10.7 GB, 10737418240 bytes, 20971520 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk label type: dos
Disk identifier: 0x714b81a4

   Device Boot      Start         End      Blocks   Id  System
/dev/sdb1            2048    20971519    10484736    5  Extended
/dev/sdb5            4096     3909631     1952768   83  Linux

Disk /dev/sdc: 10.7 GB, 10737418240 bytes, 20971520 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes

Disk /dev/mapper/rootvg-root: 61.2 GB, 61194895360 bytes, 119521280 sector
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes

Disk /dev/mapper/rootvg-swap: 2147 MB, 2147483648 bytes, 4194304 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes

[root@ftp:/root]
> pvscan
File descriptor 3 (pipe:[4198548]) leaked on pvscan invocation. Parent PID
  PV /dev/sda2   VG rootvg          lvm2 [<49.00 GiB / 0    free]
  PV /dev/sdc    VG rootvg          lvm2 [<10.00 GiB / 0    free]
  Total: 2 [58.99 GiB] / in use: 2 [58.99 GiB] / in no VG: 0 [0   ]

[root@ftp:/root]
> pvdisplay
File descriptor 3 (pipe:[4198548]) leaked on pvdisplay invocation. Parent
  --- Physical volume ---
  PV Name               /dev/sda2
  VG Name               rootvg
  PV Size               <49.00 GiB / not usable 3.00 MiB
  Allocatable           yes (but full)
  PE Size               4.00 MiB
  Total PE              12543
  Free PE               0
  Allocated PE          12543
  PV UUID               dXiNdh-ePAR-VhiU-PPOy-seF2-eezg-AYAwx5

  --- Physical volume ---
  PV Name               /dev/sdc
  VG Name               rootvg
  PV Size               10.00 GiB / not usable 4.00 MiB
  Allocatable           yes (but full)
  PE Size               4.00 MiB
  Total PE              2559
  Free PE               0
  Allocated PE          2559
  PV UUID               YkDJG5-2JJp-DX2c-mGpS-QMn7-796E-VrA1i6

[root@ftp:/root]
> pvdisplay /dev/sda2
File descriptor 3 (pipe:[4198548]) leaked on pvdisplay invocation. Parent
  --- Physical volume ---
  PV Name               /dev/sda2
  VG Name               rootvg
  PV Size               <49.00 GiB / not usable 3.00 MiB
  Allocatable           yes (but full)
  PE Size               4.00 MiB
  Total PE              12543
  Free PE               0
  Allocated PE          12543
  PV UUID               dXiNdh-ePAR-VhiU-PPOy-seF2-eezg-AYAwx5

[root@ftp:/root]
> vgscan
File descriptor 3 (pipe:[4198548]) leaked on vgscan invocation. Parent PID
  Reading volume groups from cache.
  Found volume group "rootvg" using metadata type lvm2

[root@ftp:/root]
> vgs
File descriptor 3 (pipe:[4198548]) leaked on vgs invocation. Parent PID 11
  VG     #PV #LV #SN Attr   VSize  VFree
  rootvg   2   2   0 wz--n- 58.99g    0 

[root@ftp:/root]
> vgdisplay
File descriptor 3 (pipe:[4198548]) leaked on vgdisplay invocation. Parent
  --- Volume group ---
  VG Name               rootvg
  System ID
  Format                lvm2
  Metadata Areas        2
  Metadata Sequence No  6
  VG Access             read/write
  VG Status             resizable
  MAX LV                0
  Cur LV                2
  Open LV               2
  Max PV                0
  Cur PV                2
  Act PV                2
  VG Size               58.99 GiB
  PE Size               4.00 MiB
  Total PE              15102
  Alloc PE / Size       15102 / 58.99 GiB
  Free  PE / Size       0 / 0
  VG UUID               jYMaK1-7oqd-rFon-EI6M-daY2-oLIX-KVuXIO

[root@ftp:/root]
> vgdisplay rootvg
File descriptor 3 (pipe:[4198548]) leaked on vgdisplay invocation. Parent
  --- Volume group ---
  VG Name               rootvg
  System ID
  Format                lvm2
  Metadata Areas        2
  Metadata Sequence No  6
  VG Access             read/write
  VG Status             resizable
  MAX LV                0
  Cur LV                2
  Open LV               2
  Max PV                0
  Cur PV                2
  Act PV                2
  VG Size               58.99 GiB
  PE Size               4.00 MiB
  Total PE              15102
  Alloc PE / Size       15102 / 58.99 GiB
  Free  PE / Size       0 / 0
  VG UUID               jYMaK1-7oqd-rFon-EI6M-daY2-oLIX-KVuXIO

[root@ftp:/root]
> lvscan
File descriptor 3 (pipe:[4198548]) leaked on lvscan invocation. Parent PID
  ACTIVE            '/dev/rootvg/swap' [2.00 GiB] inherit
  ACTIVE            '/dev/rootvg/root' [56.99 GiB] inherit

[root@ftp:/root]
> lvs
File descriptor 3 (pipe:[4198548]) leaked on lvs invocation. Parent PID 11
  LV   VG     Attr       LSize  Pool Origin Data%  Meta%  Move Log Cpy%Syn
  root rootvg -wi-ao---- 56.99g
  swap rootvg -wi-ao----  2.00g                                           

[root@ftp:/root]
> lvdisplay
File descriptor 3 (pipe:[4198548]) leaked on lvdisplay invocation. Parent
  --- Logical volume ---
  LV Path                /dev/rootvg/swap
  LV Name                swap
  VG Name                rootvg
  LV UUID                WySyzT-x2br-xtfU-Grbg-GjAj-KorV-m8yZvo
  LV Write Access        read/write
  LV Creation host, time MiWiFi-R3L-srv, 2018-02-28 09:37:10 +0800
  LV Status              available
  # open                 2
  LV Size                2.00 GiB
  Current LE             512
  Segments               1
  Allocation             inherit
  Read ahead sectors     auto
  - currently set to     8192
  Block device           253:1

  --- Logical volume ---
  LV Path                /dev/rootvg/root
  LV Name                root
  VG Name                rootvg
  LV UUID                t71Wnu-l8eu-LZbw-GKew-jKTS-GxdF-d7XL5F
  LV Write Access        read/write
  LV Creation host, time MiWiFi-R3L-srv, 2018-02-28 09:37:11 +0800
  LV Status              available
  # open                 1
  LV Size                56.99 GiB
  Current LE             14590
  Segments               2
  Allocation             inherit
  Read ahead sectors     auto
  - currently set to     8192
  Block device           253:0

[root@ftp:/root]
> lvdisplay /dev/rootvg/root
File descriptor 3 (pipe:[4198548]) leaked on lvdisplay invocation. Parent
  --- Logical volume ---
  LV Path                /dev/rootvg/root
  LV Name                root
  VG Name                rootvg
  LV UUID                t71Wnu-l8eu-LZbw-GKew-jKTS-GxdF-d7XL5F
  LV Write Access        read/write
  LV Creation host, time MiWiFi-R3L-srv, 2018-02-28 09:37:11 +0800
  LV Status              available
  # open                 1
  LV Size                56.99 GiB
  Current LE             14590
  Segments               2
  Allocation             inherit
  Read ahead sectors     auto
  - currently set to     8192
  Block device           253:0

[root@ftp:/root]
> df -TH
Filesystem                               Type      Size  Used Avail Use% M
/dev/mapper/centos_miwifi--r3l--srv-root xfs        51G  4.4G   47G   9% /
devtmpfs                                 devtmpfs  4.1G     0  4.1G   0% /
tmpfs                                    tmpfs     4.1G   29k  4.1G   1% /
tmpfs                                    tmpfs     4.1G   26M  4.1G   1% /
tmpfs                                    tmpfs     4.1G     0  4.1G   0% /
/dev/sda1                                xfs       1.1G  150M  914M  15% /
//192.168.31.20/share                    cifs      7.8T  4.1T  3.8T  53% /
tmpfs                                    tmpfs     819M     0  819M   0% /

[root@ftp:/root]
> man lvcreate
LVCREATE(8)             System Manager's Manual             LVCREATE(8)

NAME
       lvcreate - Create a logical volume

SYNOPSIS
       lvcreate option_args position_args
           [ option_args ]
           [ position_args ]

        -a|--activate y|n|ay
           --addtag Tag
           --alloc contiguous|cling|cling_by_tags|normal|any‐
       where|inherit
        -A|--autobackup y|n
        -H|--cache
           --cachemetadataformat auto|1|2
           --cachemode writethrough|writeback|passthrough
           --cachepolicy String
           --cachepool LV
           --cachesettings String
        -c|--chunksize Size[k|UNIT]
           --commandprofile String
           --config String
        -C|--contiguous y|n
        -d|--debug
           --discards passdown|nopassdown|ignore
           --driverloaded y|n
           --errorwhenfull y|n
        -l|--extents Number[PERCENT]
        -h|--help
        -K|--ignoreactivationskip
           --ignoremonitoring
           --longhelp
        -j|--major Number
           --[raid]maxrecoveryrate Size[k|UNIT]
           --metadataprofile String
           --minor Number
           --[raid]minrecoveryrate Size[k|UNIT]
           --mirrorlog core|disk
        -m|--mirrors Number
           --monitor y|n
        -n|--name String
           --nosync
           --noudevsync
        -p|--permission rw|r
        -M|--persistent y|n
           --poolmetadatasize Size[m|UNIT]
           --poolmetadataspare y|n
           --profile String
        -q|--quiet
        -r|--readahead auto|none|Number
        -R|--regionsize Size[m|UNIT]
           --reportformat basic|json
        -k|--setactivationskip y|n
        -L|--size Size[m|UNIT]
        -s|--snapshot
        -i|--stripes Number
        -I|--stripesize Size[k|UNIT]
        -t|--test
        -T|--thin
           --thinpool LV
           --type linear|striped|snapshot|mir‐
       ror|raid|thin|cache|thin-pool|cache-pool
        -v|--verbose
           --version
        -V|--virtualsize Size[m|UNIT]
        -W|--wipesignatures y|n
        -y|--yes
        -Z|--zero y|n

DESCRIPTION
       lvcreate  creates  a  new  LV  in  a  VG. For standard LVs, this
       requires allocating logical extents from the VG's free  physical
       extents.  If  there  is  not  enough  free  space, the VG can be
       extended with other PVs (vgextend(8)), or existing  LVs  can  be
       reduced or removed (lvremove(8), lvreduce(8).)

       To  control which PVs a new LV will use, specify one or more PVs
       as position args at the end of the command line.  lvcreate  will
       allocate physical extents only from the specified PVs.

       lvcreate  can  also  create  snapshots of existing LVs, e.g. for
       backup purposes. The data in a new snapshot  LV  represents  the
       content  of  the original LV from the time the snapshot was cre‐
       ated.

       RAID LVs can be created by specifying an LV type  when  creating
       the LV (see lvmraid(7)). Different RAID levels require different
       numbers of unique PVs be available in the VG for allocation.

       Thin pools (for thin provisioning) and cache pools (for caching)
       are   represented  by  special  LVs  with  types  thin-pool  and
       cache-pool (see lvmthin(7) and lvmcache(7)). The  pool  LVs  are
       not  usable  as  standard block devices, but the LV names act as
       references to the pools.

       Thin LVs are thinly provisioned from a thin pool, and  are  cre‐
       ated with a virtual size rather than a physical size. A cache LV
       is the combination of a standard LV with a cache pool,  used  to
       cache active portions of the LV to improve performance.

   Usage notes
       In  the  usage  section  below, --size Size can be replaced with
       --extents Number. See descriptions in the options section.

       In the usage section below, --name is omitted from the  required
       options,  even though it is typically used. When the name is not
       specified, a new LV name is generated with the "lvol" prefix and
       a unique numeric suffix.

USAGE
       Create a linear LV.

       lvcreate -L|--size Size[m|UNIT] VG
           [ -l|--extents Number[PERCENT] ]
           [    --type linear ]
           [ COMMON_OPTIONS ]
           [ PV ... ]
       -

       Create a striped LV (infers --type striped).

       lvcreate -i|--stripes Number -L|--size Size[m|UNIT] VG
           [ -l|--extents Number[PERCENT] ]
           [ -I|--stripesize Size[k|UNIT] ]
           [ COMMON_OPTIONS ]
           [ PV ... ]
       -

       Create a raid1 or mirror LV (infers --type raid1|mirror).

       lvcreate -m|--mirrors Number -L|--size Size[m|UNIT] VG
           [ -l|--extents Number[PERCENT] ]
           [ -R|--regionsize Size[m|UNIT] ]
           [    --mirrorlog core|disk ]
           [    --[raid]minrecoveryrate Size[k|UNIT] ]
           [    --[raid]maxrecoveryrate Size[k|UNIT] ]
           [ COMMON_OPTIONS ]
           [ PV ... ]
       -

       Create  a  raid  LV  (a  specific  raid level must be used, e.g.
       raid1).

       lvcreate --type raid -L|--size Size[m|UNIT] VG
           [ -l|--extents Number[PERCENT] ]
           [ -m|--mirrors Number ]
           [ -i|--stripes Number ]
           [ -I|--stripesize Size[k|UNIT] ]
           [ -R|--regionsize Size[m|UNIT] ]
           [    --[raid]minrecoveryrate Size[k|UNIT] ]
           [    --[raid]maxrecoveryrate Size[k|UNIT] ]
           [ COMMON_OPTIONS ]
           [ PV ... ]
       -

       Create a raid10 LV.

       lvcreate -m|--mirrors Number -i|--stripes Number
             -L|--size Size[m|UNIT] VG
           [ -l|--extents Number[PERCENT] ]
           [ -I|--stripesize Size[k|UNIT] ]
           [ -R|--regionsize Size[m|UNIT] ]
           [    --[raid]minrecoveryrate Size[k|UNIT] ]
           [    --[raid]maxrecoveryrate Size[k|UNIT] ]
           [ COMMON_OPTIONS ]
           [ PV ... ]
       -

       Create a COW snapshot LV of an origin LV.

       lvcreate -s|--snapshot -L|--size Size[m|UNIT] LV
           [ -l|--extents Number[PERCENT] ]
           [ -i|--stripes Number ]
           [ -I|--stripesize Size[k|UNIT] ]
           [ -c|--chunksize Size[k|UNIT] ]
           [    --type snapshot ]
           [ COMMON_OPTIONS ]
           [ PV ... ]
       -

       Create a thin pool.

       lvcreate --type thin-pool -L|--size Size[m|UNIT] VG
           [ -l|--extents Number[PERCENT] ]
           [ -c|--chunksize Size[k|UNIT] ]
           [ -i|--stripes Number ]
           [ -I|--stripesize Size[k|UNIT] ]
           [    --thinpool LV_new ]
           [    --poolmetadatasize Size[m|UNIT] ]
           [    --poolmetadataspare y|n ]
           [    --discards passdown|nopassdown|ignore ]
           [    --errorwhenfull y|n ]
           [ COMMON_OPTIONS ]
           [ PV ... ]
       -

       Create a cache pool.

       lvcreate --type cache-pool -L|--size Size[m|UNIT] VG
           [ -l|--extents Number[PERCENT] ]
           [ -H|--cache ]
           [ -c|--chunksize Size[k|UNIT] ]
           [    --poolmetadatasize Size[m|UNIT] ]
           [    --poolmetadataspare y|n ]
           [    --cachemode writethrough|writeback|passthrough ]
           [    --cachepolicy String ]
           [    --cachesettings String ]
           [    --cachemetadataformat auto|1|2 ]
           [ COMMON_OPTIONS ]
           [ PV ... ]
       -

       Create a thin LV in a thin pool (infers --type thin).

       lvcreate -V|--virtualsize Size[m|UNIT] --thinpool LV_thinpool VG
           [ -T|--thin ]
           [    --type thin ]
           [    --discards passdown|nopassdown|ignore ]
           [    --errorwhenfull y|n ]
           [ COMMON_OPTIONS ]
       -

       Create a thin LV that is a snapshot of an existing thin LV
       (infers --type thin).

       lvcreate -s|--snapshot LV_thin
           [    --type thin ]
           [    --discards passdown|nopassdown|ignore ]
           [    --errorwhenfull y|n ]
           [ COMMON_OPTIONS ]
       -

       Create a thin LV that is a snapshot of an external origin LV.

       lvcreate --type thin --thinpool LV_thinpool LV
           [ -T|--thin ]
           [ -c|--chunksize Size[k|UNIT] ]
           [    --poolmetadatasize Size[m|UNIT] ]
           [    --poolmetadataspare y|n ]
           [    --discards passdown|nopassdown|ignore ]
           [    --errorwhenfull y|n ]
           [ COMMON_OPTIONS ]
       -

       Create a thin LV, first creating a thin pool for it,
       where the new thin pool is named by the --thinpool arg.

       lvcreate --type thin -V|--virtualsize Size[m|UNIT]
             -L|--size Size[m|UNIT] --thinpool LV_new
           [ -l|--extents Number[PERCENT] ]
           [ -T|--thin ]
           [ -c|--chunksize Size[k|UNIT] ]
           [ -i|--stripes Number ]
           [ -I|--stripesize Size[k|UNIT] ]
           [    --poolmetadatasize Size[m|UNIT] ]
           [    --poolmetadataspare y|n ]
           [    --discards passdown|nopassdown|ignore ]
           [    --errorwhenfull y|n ]
           [ COMMON_OPTIONS ]
           [ PV ... ]
       -

       Create a cache LV, first creating a new origin LV,
       then combining it with the existing cache pool named
       by the --cachepool arg.

       lvcreate --type cache -L|--size Size[m|UNIT]
             --cachepool LV_cachepool VG
           [ -l|--extents Number[PERCENT] ]
           [ -H|--cache ]
           [ -c|--chunksize Size[k|UNIT] ]
           [ -i|--stripes Number ]
           [ -I|--stripesize Size[k|UNIT] ]
           [    --poolmetadatasize Size[m|UNIT] ]
           [    --poolmetadataspare y|n ]
           [    --cachemode writethrough|writeback|passthrough ]
           [    --cachepolicy String ]
           [    --cachesettings String ]
           [    --cachemetadataformat auto|1|2 ]
           [ COMMON_OPTIONS ]
           [ PV ... ]
       -

       Common options for command:
           [ -a|--activate y|n|ay ]
           [ -A|--autobackup y|n ]
           [ -C|--contiguous y|n ]
           [ -K|--ignoreactivationskip ]
           [ -j|--major Number ]
           [ -n|--name String ]
           [ -p|--permission rw|r ]
           [ -M|--persistent y|n ]
           [ -r|--readahead auto|none|Number ]
           [ -k|--setactivationskip y|n ]
           [ -W|--wipesignatures y|n ]
           [ -Z|--zero y|n ]
           [    --addtag Tag ]
           [    --alloc contiguous|cling|cling_by_tags|normal|any‐
           where|inherit ]
           [    --ignoremonitoring ]
           [    --metadataprofile String ]
           [    --minor Number ]
           [    --monitor y|n ]
           [    --nosync ]
           [    --noudevsync ]
           [    --reportformat basic|json ]

       Common options for lvm:
           [ -d|--debug ]
           [ -h|--help ]
           [ -q|--quiet ]
           [ -t|--test ]
           [ -v|--verbose ]
           [ -y|--yes ]
           [    --commandprofile String ]
           [    --config String ]
           [    --driverloaded y|n ]
           [    --longhelp ]
           [    --profile String ]
           [    --version ]

OPTIONS
       -a|--activate y|n|ay
              Controls the active state of the new LV.  y makes the LV
              active, or available.  New LVs are made active by
              default.  n makes the LV inactive, or unavailable, only
              when possible.  In some cases, creating an LV requires it
              to be active.  For example, COW snapshots of an active
              origin LV can only be created in the active state (this
              does not apply to thin snapshots).  The --zero option
              normally requires the LV to be active.  If autoactivation
              ay is used, the LV is only activated if it matches an
              item in lvm.conf activation/auto_activation_volume_list.
              ay implies --zero n and --wipesignatures n.  See lvm‐
              lockd(8) for more information about activation options
              for shared VGs.  See clvmd(8) for more information about
              activation options for clustered VGs.

       --addtag Tag
              Adds a tag to a PV, VG or LV. This option can be repeated
              to add multiple tags at once. See lvm(8) for information
              about tags.

       --alloc contiguous|cling|cling_by_tags|normal|anywhere|inherit
              Determines the allocation policy when a command needs to
              allocate Physical Extents (PEs) from the VG. Each VG and
              LV has an allocation policy which can be changed with
              vgchange/lvchange, or overriden on the command line.
              normal applies common sense rules such as not placing
              parallel stripes on the same PV.  inherit applies the VG
              policy to an LV.  contiguous requires new PEs be placed
              adjacent to existing PEs.  cling places new PEs on the
              same PV as existing PEs in the same stripe of the LV.  If
              there are sufficient PEs for an allocation, but normal
              does not use them, anywhere will use them even if it
              reduces performance, e.g. by placing two stripes on the
              same PV.  Optional positional PV args on the command line
              can also be used to limit which PVs the command will use
              for allocation.  See lvm(8) for more information about
              allocation.

       -A|--autobackup y|n
              Specifies if metadata should be backed up automatically
              after a change.  Enabling this is strongly advised! See
              vgcfgbackup(8) for more information.

       -H|--cache
              Specifies the command is handling a cache LV or cache
              pool.  See --type cache and --type cache-pool.  See lvm‐
              cache(7) for more information about LVM caching.

       --cachemetadataformat auto|1|2
              Specifies the cache metadata format used by cache target.

       --cachemode writethrough|writeback|passthrough
              Specifies when writes to a cache LV should be considered
              complete.  writeback considers a write complete as soon
              as it is stored in the cache pool.  writethough considers
              a write complete only when it has been stored in both the
              cache pool 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. With passthrough, all reads are served from the ori‐
              gin LV (all reads miss the cache) and all writes are for‐
              warded to the origin LV; additionally, write hits cause
              cache block invalidates. See lvmcache(7) for more infor‐
              mation.

       --cachepolicy String
              Specifies the cache policy for a cache LV.  See lvm‐
              cache(7) for more information.

       --cachepool LV
              The name of a cache pool LV.

       --cachesettings String
              Specifies tunable values for a cache LV in "Key = Value"
              form.  Repeat this option to specify multiple values.
              (The default values should usually be adequate.)  The
              special string value default switches settings back to
              their default kernel values and removes them from the
              list of settings stored in LVM metadata.  See lvmcache(7)
              for more information.

       -c|--chunksize Size[k|UNIT]
              The size of chunks in a snapshot, cache pool or thin
              pool.  For snapshots, the value must be a power of 2
              between 4KiB and 512KiB and the default value is 4.  For
              a cache pool the value must be between 32KiB and 1GiB and
              the default value is 64.  For a thin pool 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 speci‐
              fied.  The value must be a multiple of 64KiB.  See
              lvmthin(7) and lvmcache(7) for more information.

       --commandprofile String
              The command profile to use for command configuration.
              See lvm.conf(5) for more information about profiles.

       --config String
              Config settings for the command. These override lvm.conf
              settings.  The String arg uses the same format as
              lvm.conf, or may use section/field syntax.  See
              lvm.conf(5) for more information about config.

       -C|--contiguous y|n
              Sets or resets the contiguous allocation policy for LVs.
              Default is no contiguous allocation based on a next free
              principle.  It is only possible to change a non-contigu‐
              ous allocation policy to contiguous if all of the allo‐
              cated physical extents in the LV are already contiguous.

       -d|--debug ...
              Set debug level. Repeat from 1 to 6 times to increase the
              detail of messages sent to the log file and/or syslog (if
              configured).

       --discards passdown|nopassdown|ignore
              Specifies how the device-mapper thin pool layer in the
              kernel should handle discards.  ignore causes the thin
              pool to ignore discards.  nopassdown causes the thin pool
              to process discards itself to allow reuse of unneeded
              extents in the thin pool.  passdown causes the thin pool
              to process discards itself (like nopassdown) and pass the
              discards to the underlying device.  See lvmthin(7) for
              more information.

       --driverloaded y|n
              If set to no, the command will not attempt to use device-
              mapper.  For testing and debugging.

       --errorwhenfull y|n
              Specifies thin pool behavior when data space is
              exhausted.  When yes, device-mapper will immediately
              return an error when a thin pool is full and an I/O
              request requires space.  When no, device-mapper will
              queue these I/O requests for a period of time to allow
              the thin pool to be extended.  Errors are returned if no
              space is available after the timeout.  (Also see dm-
              thin-pool kernel module option no_space_timeout.)  See
              lvmthin(7) for more information.

       -l|--extents Number[PERCENT]
              Specifies the size of the new LV in logical extents.  The
              --size and --extents options are alternate methods of
              specifying size.  The total number of physical extents
              used will be greater when redundant data is needed for
              RAID levels.  An alternate syntax allows the size to be
              determined indirectly as a percentage of the size of a
              related VG, LV, or set of PVs. The suffix %VG denotes the
              total size of the VG, the suffix %FREE the remaining free
              space in the VG, and the suffix %PVS the free space in
              the specified PVs.  For a snapshot, the size can be
              expressed as a percentage of the total size of the origin
              LV with the suffix %ORIGIN (100%ORIGIN provides space for
              the whole origin).  When expressed as a percentage, the
              size defines an upper limit for the number of logical
              extents in the new LV. The precise number of logical
              extents in the new LV is not determined until the command
              has completed.

       -h|--help
              Display help text.

       -K|--ignoreactivationskip
              Ignore the "activation skip" LV flag during activation to
              allow LVs with the flag set to be activated.

       --ignoremonitoring
              Do not interact with dmeventd unless --monitor is speci‐
              fied.  Do not use this if dmeventd is already monitoring
              a device.

       --longhelp
              Display long help text.

       -j|--major Number
              Sets the major number of an LV block device.

       --[raid]maxrecoveryrate Size[k|UNIT]
              Sets the maximum recovery rate for a RAID LV.  The rate
              value is an amount of data per second for each device in
              the array.  Setting the rate to 0 means it will be
              unbounded.  See lvmraid(7) for more information.

       --metadataprofile String
              The metadata profile to use for command configuration.
              See lvm.conf(5) for more information about profiles.

       --minor Number
              Sets the minor number of an LV block device.

       --[raid]minrecoveryrate Size[k|UNIT]
              Sets the minimum recovery rate for a RAID LV.  The rate
              value is an amount of data per second for each device in
              the array.  Setting the rate to 0 means it will be
              unbounded.  See lvmraid(7) for more information.

       --mirrorlog core|disk
              Specifies the type of mirror log for LVs with the "mir‐
              ror" type (does not apply to the "raid1" type.)  disk is
              a persistent log and requires a small amount of storage
              space, usually on a separate device from the data being
              mirrored.  core is not persistent; the log is kept only
              in memory.  In this case, the mirror must be synchronized
              (by copying LV data from the first device to others) each
              time the LV is activated, e.g. after reboot.  mirrored is
              a persistent log that is itself mirrored, but should be
              avoided. Instead, use the raid1 type for log redundancy.

       -m|--mirrors Number
              Specifies the number of mirror images in addition to the
              original LV image, e.g. --mirrors 1 means there are two
              images of the data, the original and one mirror image.
              Optional positional PV args on the command line can spec‐
              ify the devices the images should be placed on.  There
              are two mirroring implementations: "raid1" and "mirror".
              These are the names of the corresponding LV types, or
              "segment types".  Use the --type option to specify which
              to use (raid1 is default, and mirror is legacy) Use
              lvm.conf global/mirror_segtype_default and
              global/raid10_segtype_default to configure the default
              types.  See the --nosync option for avoiding initial
              image synchronization.  See lvmraid(7) for more informa‐
              tion.

       --monitor y|n
              Start (yes) or stop (no) monitoring an LV with dmeventd.
              dmeventd monitors kernel events for an LV, and performs
              automated maintenance for the LV in reponse to specific
              events.  See dmeventd(8) for more information.

       -n|--name String
              Specifies the name of a new LV.  When unspecified, a
              default name of "lvol#" is generated, where # is a number
              generated by LVM.

       --nosync
              Causes the creation of mirror, raid1, raid4, raid5 and
              raid10 to skip the initial synchronization. In case of
              mirror, raid1 and raid10, any data written afterwards
              will be mirrored, but the original contents will not be
              copied. In case of raid4 and raid5, no parity blocks will
              be written, though any data written afterwards will cause
              parity blocks to be stored.  This is useful for skipping
              a potentially long and resource intensive initial sync of
              an empty mirror/raid1/raid4/raid5 and raid10 LV.  This
              option is not valid for raid6, because raid6 relies on
              proper parity (P and Q Syndromes) being created during
              initial synchronization in order to reconstruct proper
              user date in case of device failures.  raid0 and
              raid0_meta do not provide any data copies or parity sup‐
              port and thus do not support initial synchronization.

       --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. Only
              use this if udev is not running or has rules that ignore
              the devices LVM creates.

       -p|--permission rw|r
              Set access permission to read only r or read and write
              rw.

       -M|--persistent y|n
              When yes, makes the specified minor number persistent.

       --poolmetadatasize Size[m|UNIT]
              Specifies the size of the new pool metadata LV.

       --poolmetadataspare y|n
              Enable or disable the automatic creation and management
              of a spare pool metadata LV in the VG. A spare metadata
              LV is reserved space that can be used when repairing a
              pool.

       --profile String
              An alias for --commandprofile or --metadataprofile,
              depending on the command.

       -q|--quiet ...
              Suppress output and log messages. Overrides --debug and
              --verbose.  Repeat once to also suppress any prompts with
              answer 'no'.

       -r|--readahead auto|none|Number
              Sets read ahead sector count of an LV.  auto is the
              default which allows the kernel to choose a suitable
              value automatically.  none is equivalent to zero.

       -R|--regionsize Size[m|UNIT]
              Size of each raid or mirror synchronization region.
              lvm.conf activation/raid_region_size can be used to con‐
              figure a default.

       --reportformat basic|json
              Overrides current output format for reports which is
              defined globally by the report/output_format setting in
              lvm.conf.  basic is the original format with columns and
              rows.  If there is more than one report per command, each
              report is prefixed with the report name for identifica‐
              tion. json produces report output in JSON format. See
              lvmreport(7) for more information.

       -k|--setactivationskip y|n
              Persistently sets (yes) or clears (no) the "activation
              skip" flag on an LV.  An LV with this flag set is not
              activated unless the --ignoreactivationskip option is
              used by the activation command.  This flag is set by
              default on new thin snapshot LVs.  The flag is not
              applied to deactivation.  The current value of the flag
              is indicated in the lvs lv_attr bits.

       -L|--size Size[m|UNIT]
              Specifies the size of the new LV.  The --size and
              --extents options are alternate methods of specifying
              size.  The total number of physical extents used will be
              greater when redundant data is needed for RAID levels.

       -s|--snapshot
              Create a snapshot. Snapshots provide a "frozen image" of
              an origin LV.  The snapshot LV can be used, e.g. for
              backups, while the origin LV continues to be used.  This
              option can create a COW (copy on write) snapshot, or a
              thin snapshot (in a thin pool.)  Thin snapshots are cre‐
              ated when the origin is a thin LV and the size option is
              NOT specified. Thin snapshots share the same blocks in
              the thin pool, and do not allocate new space from the VG.
              Thin snapshots are created with the "activation skip"
              flag, see --setactivationskip.  A thin snapshot of a non-
              thin "external origin" LV is created when a thin pool is
              specified. Unprovisioned blocks in the thin snapshot LV
              are read from the external origin LV. The external origin
              LV must be read-only.  See lvmthin(7) for more informa‐
              tion about LVM thin provisioning.  COW snapshots are cre‐
              ated when a size is specified. The size is allocated from
              space in the VG, and is the amount of space that can be
              used for saving COW blocks as writes occur to the origin
              or snapshot.  The size chosen should depend upon the
              amount of writes that are expected; often 20% of the ori‐
              gin LV is enough. If COW space runs low, it can be
              extended with lvextend (shrinking is also allowed with
              lvreduce.)  A small amount of the COW snapshot LV size is
              used to track COW block locations, so the full size is
              not available for COW data blocks.  Use lvs to check how
              much space is used, and see --monitor to to automatically
              extend the size to avoid running out of space.

       -i|--stripes Number
              Specifies the number of stripes in a striped LV. This is
              the number of PVs (devices) that a striped LV is spread
              across. Data that appears sequential in the LV is spread
              across multiple devices in units of the stripe size (see
              --stripesize). This does not change existing allocated
              space, but only applies to space being allocated by the
              command.  When creating a RAID 4/5/6 LV, this number does
              not include the extra devices that are required for par‐
              ity. The largest number depends on the RAID type (raid0:
              64, raid10: 32, raid4/5: 63, raid6: 62), and when unspec‐
              ified, the default depends on the RAID type (raid0: 2,
              raid10: 2, raid4/5: 3, raid6: 5.)  To stripe a new raid
              LV across all PVs by default, see lvm.conf alloca‐
              tion/raid_stripe_all_devices.

       -I|--stripesize Size[k|UNIT]
              The amount of data that is written to one device before
              moving to the next in a striped LV.

       -t|--test
              Run in test mode. Commands will not update metadata.
              This is implemented by disabling all metadata writing but
              nevertheless returning success to the calling function.
              This may lead to unusual error messages in multi-stage
              operations if a tool relies on reading back metadata it
              believes has changed but hasn't.

       -T|--thin
              Specifies the command is handling a thin LV or thin pool.
              See --type thin, --type thin-pool, and --virtualsize.
              See lvmthin(7) for more information about LVM thin provi‐
              sioning.

       --thinpool LV
              The name of a thin pool LV.

       --type linear|striped|snapshot|mir‐
              ror|raid|thin|cache|thin-pool|cache-pool
              The LV type, also known as "segment type" or "segtype".
              See usage descriptions for the specific ways to use these
              types.  For more information about redundancy and perfor‐
              mance (raid<N>, mirror, striped, linear) see lvmraid(7).
              For thin provisioning (thin, thin-pool) see lvmthin(7).
              For performance caching (cache, cache-pool) see lvm‐
              cache(7).  For copy-on-write snapshots (snapshot) see
              usage definitions.  Several commands omit an explicit
              type option because the type is inferred from other
              options or shortcuts (e.g. --stripes, --mirrors, --snap‐
              shot, --virtualsize, --thin, --cache).  Use inferred
              types with care because it can lead to unexpected
              results.

       -v|--verbose ...
              Set verbose level. Repeat from 1 to 4 times to increase
              the detail of messages sent to stdout and stderr.

       --version
              Display version information.

       -V|--virtualsize Size[m|UNIT]
              The virtual size of a new thin LV.  See lvmthin(7) for
              more information about LVM thin provisioning.  Using vir‐
              tual size (-V) and actual size (-L) together creates a
              sparse LV.  lvm.conf global/sparse_segtype_default deter‐
              mines the default segment type used to create a sparse
              LV.  Anything written to a sparse LV will be returned
              when reading from it.  Reading from other areas of the LV
              will return blocks of zeros.  When using a snapshot to
              create a sparse LV, a hidden virtual device is created
              using the zero target, and the LV has the suffix
              _vorigin.  Snapshots are less efficient than thin provi‐
              sioning when creating large sparse LVs (GiB).

       -W|--wipesignatures y|n
              Controls detection and subsequent wiping of signatures on
              new LVs.  There is a prompt for each signature detected
              to confirm its wiping (unless --yes is used to override
              confirmations.)  When not specified, signatures are wiped
              whenever zeroing is done (see --zero). This behaviour can
              be configured with lvm.conf allocation/wipe_signa‐
              tures_when_zeroing_new_lvs.  If blkid wiping is used
              (lvm.conf allocation/use_blkid_wiping) and LVM is com‐
              piled with blkid wiping support, then the blkid(8)
              library is used to detect the signatures (use blkid -k to
              list the signatures that are recognized).  Otherwise,
              native LVM code is used to detect signatures (only MD
              RAID, swap and LUKS signatures are detected in this
              case.)  The LV is not wiped if the read only flag is set.

       -y|--yes
              Do not prompt for confirmation interactively but always
              assume the answer yes. Use with extreme caution.  (For
              automatic no, see -qq.)

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

VARIABLES
       VG
              Volume  Group  name.   See  lvm(8)  for valid names.  For
              lvcreate, the required VG positional arg may  be  omitted
              when  the  VG  name  is  included in another option, e.g.
              --name VG/LV.

       LV
              Logical Volume name.  See lvm(8) for valid names.  An  LV
              positional  arg  generally  includes  the  VG name and LV
              name, e.g. VG/LV.  LV followed by _<type> indicates  that
              an  LV  of  the  given type is required. (raid represents
              raid<N> type)

       PV
              Physical Volume name, a device path under /dev.  For com‐
              mands managing physical extents, a PV positional arg gen‐
              erally accepts a suffix indicating a range  (or  multiple
              ranges)  of  physical extents (PEs). When the first PE is
              omitted, it defaults to the start of the device, and when
              the last PE is omitted it defaults to end.  Start and end
              range (inclusive): PV[:PE-PE]...  Start and length  range
              (counting from 0): PV[:PE+PE]...

       String
              See  the  option  description  for  information about the
              string content.

       Size[UNIT]
              Size is an input number that accepts  an  optional  unit.
              Input  units  are  always  treated  as  base  two values,
              regardless of capitalization, e.g. 'k' and 'K' both refer
              to  1024.  The default input unit is specified by letter,
              followed by |UNIT.  UNIT represents other possible  input
              units: bBsSkKmMgGtTpPeE.  b|B is bytes, s|S is sectors of
              512 bytes, k|K is kilobytes, m|M  is  megabytes,  g|G  is
              gigabytes,  t|T  is  terabytes,  p|P is petabytes, e|E is
              exabytes.  (This should not be confused with  the  output
              control  --units,  where capital letters mean multiple of
              1000.)

ENVIRONMENT VARIABLES
       See lvm(8) for information about environment variables  used  by
       lvm.   For example, LVM_VG_NAME can generally be substituted for
       a required VG parameter.

ADVANCED USAGE
       Alternate command forms, advanced command usage, and listing  of
       all valid syntax for completeness.

       Create an LV that returns errors when used.

       lvcreate --type error -L|--size Size[m|UNIT] VG
           [ -l|--extents Number[PERCENT] ]
           [ COMMON_OPTIONS ]
       -

       Create an LV that returns zeros when read.

       lvcreate --type zero -L|--size Size[m|UNIT] VG
           [ -l|--extents Number[PERCENT] ]
           [ COMMON_OPTIONS ]
       -

       Create a linear LV.

       lvcreate --type linear -L|--size Size[m|UNIT] VG
           [ -l|--extents Number[PERCENT] ]
           [ COMMON_OPTIONS ]
           [ PV ... ]
       -

       Create a striped LV (also see lvcreate --stripes).

       lvcreate --type striped -L|--size Size[m|UNIT] VG
           [ -l|--extents Number[PERCENT] ]
           [ -i|--stripes Number ]
           [ -I|--stripesize Size[k|UNIT] ]
           [ COMMON_OPTIONS ]
           [ PV ... ]
       -

       Create a mirror LV (also see --type raid1).

       lvcreate --type mirror -L|--size Size[m|UNIT] VG
           [ -l|--extents Number[PERCENT] ]
           [ -m|--mirrors Number ]
           [ -R|--regionsize Size[m|UNIT] ]
           [ -i|--stripes Number ]
           [ -I|--stripesize Size[k|UNIT] ]
           [    --mirrorlog core|disk ]
           [ COMMON_OPTIONS ]
           [ PV ... ]
       -

       Create a COW snapshot LV of an origin LV
       (also see --snapshot).

       lvcreate --type snapshot -L|--size Size[m|UNIT] LV
           [ -l|--extents Number[PERCENT] ]
           [ -s|--snapshot ]
           [ -i|--stripes Number ]
           [ -I|--stripesize Size[k|UNIT] ]
           [ -c|--chunksize Size[k|UNIT] ]
           [ COMMON_OPTIONS ]
           [ PV ... ]
       -

       Create a sparse COW snapshot LV of a virtual origin LV
       (also see --snapshot).

       lvcreate --type snapshot -L|--size Size[m|UNIT]
             -V|--virtualsize Size[m|UNIT] VG
           [ -l|--extents Number[PERCENT] ]
           [ -s|--snapshot ]
           [ -c|--chunksize Size[k|UNIT] ]
           [ COMMON_OPTIONS ]
           [ PV ... ]
       -

       Create a sparse COW snapshot LV of a virtual origin LV.

       lvcreate -s|--snapshot -L|--size Size[m|UNIT]
             -V|--virtualsize Size[m|UNIT] VG
           [ -l|--extents Number[PERCENT] ]
           [ -c|--chunksize Size[k|UNIT] ]
           [    --type snapshot ]
           [ COMMON_OPTIONS ]
           [ PV ... ]
       -

       Create a thin pool (infers --type thin-pool).

       lvcreate -T|--thin -L|--size Size[m|UNIT] VG
           [ -l|--extents Number[PERCENT] ]
           [ -c|--chunksize Size[k|UNIT] ]
           [ -i|--stripes Number ]
           [ -I|--stripesize Size[k|UNIT] ]
           [    --type thin-pool ]
           [    --poolmetadatasize Size[m|UNIT] ]
           [    --poolmetadataspare y|n ]
           [    --discards passdown|nopassdown|ignore ]
           [    --errorwhenfull y|n ]
           [ COMMON_OPTIONS ]
           [ PV ... ]
       -

       Create a thin pool named by the --thinpool arg
       (infers --type thin-pool).

       lvcreate -L|--size Size[m|UNIT] --thinpool LV_new VG
           [ -l|--extents Number[PERCENT] ]
           [ -T|--thin ]
           [ -c|--chunksize Size[k|UNIT] ]
           [ -i|--stripes Number ]
           [ -I|--stripesize Size[k|UNIT] ]
           [    --type thin-pool ]
           [    --poolmetadatasize Size[m|UNIT] ]
           [    --poolmetadataspare y|n ]
           [    --discards passdown|nopassdown|ignore ]
           [    --errorwhenfull y|n ]
           [ COMMON_OPTIONS ]
           [ PV ... ]
       -

       Create a cache pool named by the --cachepool arg
       (variant, uses --cachepool in place of --name).

       lvcreate --type cache-pool -L|--size Size[m|UNIT]
             --cachepool LV_new VG
           [ -l|--extents Number[PERCENT] ]
           [ -H|--cache ]
           [ -c|--chunksize Size[k|UNIT] ]
           [    --poolmetadatasize Size[m|UNIT] ]
           [    --poolmetadataspare y|n ]
           [    --cachemode writethrough|writeback|passthrough ]
           [    --cachepolicy String ]
           [    --cachesettings String ]
           [    --cachemetadataformat auto|1|2 ]
           [ COMMON_OPTIONS ]
           [ PV ... ]
       -

       Create a thin LV in a thin pool.

       lvcreate --type thin -V|--virtualsize Size[m|UNIT]
             --thinpool LV_thinpool VG
           [ -T|--thin ]
           [ -c|--chunksize Size[k|UNIT] ]
           [    --poolmetadatasize Size[m|UNIT] ]
           [    --poolmetadataspare y|n ]
           [    --discards passdown|nopassdown|ignore ]
           [    --errorwhenfull y|n ]
           [ COMMON_OPTIONS ]
       -

       Create a thin LV in a thin pool named in the first arg
       (variant, also see --thinpool for naming pool).

       lvcreate --type thin -V|--virtualsize Size[m|UNIT] LV_thinpool
           [ -T|--thin ]
           [    --discards passdown|nopassdown|ignore ]
           [    --errorwhenfull y|n ]
           [ COMMON_OPTIONS ]
       -

       Create a thin LV in the thin pool named in the first arg
       (variant, infers --type thin, also see --thinpool for
       naming pool.)

       lvcreate -V|--virtualsize Size[m|UNIT] LV_thinpool
           [ -T|--thin ]
           [    --type thin ]
           [    --discards passdown|nopassdown|ignore ]
           [    --errorwhenfull y|n ]
           [ COMMON_OPTIONS ]
       -

       Create a thin LV that is a snapshot of an existing thin LV.

       lvcreate --type thin LV_thin
           [ -T|--thin ]
           [    --discards passdown|nopassdown|ignore ]
           [    --errorwhenfull y|n ]
           [ COMMON_OPTIONS ]
       -

       Create a thin LV that is a snapshot of an existing thin LV
       (infers --type thin).

       lvcreate -T|--thin LV_thin
           [    --type thin ]
           [    --discards passdown|nopassdown|ignore ]
           [    --errorwhenfull y|n ]
           [ COMMON_OPTIONS ]
       -

       Create a thin LV that is a snapshot of an external origin LV
       (infers --type thin).

       lvcreate -s|--snapshot --thinpool LV_thinpool LV
           [    --type thin ]
           [    --discards passdown|nopassdown|ignore ]
           [    --errorwhenfull y|n ]
           [ COMMON_OPTIONS ]
       -

       Create a thin LV, first creating a thin pool for it,
       where the new thin pool is named by the --thinpool arg
       (variant, infers --type thin).

       lvcreate -V|--virtualsize Size[m|UNIT] -L|--size Size[m|UNIT]
             --thinpool LV_new
           [ -l|--extents Number[PERCENT] ]
           [ -T|--thin ]
           [ -c|--chunksize Size[k|UNIT] ]
           [ -i|--stripes Number ]
           [ -I|--stripesize Size[k|UNIT] ]
           [    --poolmetadatasize Size[m|UNIT] ]
           [    --poolmetadataspare y|n ]
           [    --discards passdown|nopassdown|ignore ]
           [    --errorwhenfull y|n ]
           [ COMMON_OPTIONS ]
           [ PV ... ]
       -

       Create a thin LV, first creating a thin pool for it,
       where the new thin pool is named by the --thinpool arg
       (variant, infers --type thin).

       lvcreate -V|--virtualsize Size[m|UNIT] -L|--size Size[m|UNIT]
             --thinpool LV_new VG
           [ -l|--extents Number[PERCENT] ]
           [ -T|--thin ]
           [ -c|--chunksize Size[k|UNIT] ]
           [ -i|--stripes Number ]
           [ -I|--stripesize Size[k|UNIT] ]
           [    --poolmetadatasize Size[m|UNIT] ]
           [    --poolmetadataspare y|n ]
           [    --discards passdown|nopassdown|ignore ]
           [    --errorwhenfull y|n ]
           [ COMMON_OPTIONS ]
           [ PV ... ]
       -

       Create a thin LV, first creating a thin pool for it,
       where the new thin pool is named in the first arg,
       or the new thin pool name is generated when the first
       arg is a VG name.

       lvcreate --type thin -V|--virtualsize Size[m|UNIT]
             -L|--size Size[m|UNIT] VG|LV_new
           [ -l|--extents Number[PERCENT] ]
           [ -T|--thin ]
           [ -c|--chunksize Size[k|UNIT] ]
           [ -i|--stripes Number ]
           [ -I|--stripesize Size[k|UNIT] ]
           [    --poolmetadatasize Size[m|UNIT] ]
           [    --poolmetadataspare y|n ]
           [    --discards passdown|nopassdown|ignore ]
           [    --errorwhenfull y|n ]
           [ COMMON_OPTIONS ]
           [ PV ... ]
       -

       Create a thin LV, first creating a thin pool for it,
       where the new thin pool is named in the first arg,
       or the new thin pool name is generated when the first
       arg is a VG name (variant, infers --type thin).

       lvcreate -T|--thin -V|--virtualsize Size[m|UNIT]
             -L|--size Size[m|UNIT] VG|LV_new
           [ -l|--extents Number[PERCENT] ]
           [ -c|--chunksize Size[k|UNIT] ]
           [ -i|--stripes Number ]
           [ -I|--stripesize Size[k|UNIT] ]
           [    --poolmetadatasize Size[m|UNIT] ]
           [    --poolmetadataspare y|n ]
           [    --discards passdown|nopassdown|ignore ]
           [    --errorwhenfull y|n ]
           [ COMMON_OPTIONS ]
           [ PV ... ]
       -

       Create a thin LV, first creating a thin pool for it
       (infers --type thin).
       Create a sparse snapshot of a virtual origin LV
       (infers --type snapshot).
       Chooses --type thin or --type snapshot according to
       config setting sparse_segtype_default.

       lvcreate -L|--size Size[m|UNIT] -V|--virtualsize Size[m|UNIT] VG
           [ -l|--extents Number[PERCENT] ]
           [ -s|--snapshot ]
           [ -c|--chunksize Size[k|UNIT] ]
           [ -i|--stripes Number ]
           [ -I|--stripesize Size[k|UNIT] ]
           [    --type snapshot ]
           [    --poolmetadatasize Size[m|UNIT] ]
           [    --poolmetadataspare y|n ]
           [    --discards passdown|nopassdown|ignore ]
           [    --errorwhenfull y|n ]
           [ COMMON_OPTIONS ]
           [ PV ... ]
       -

       Create a cache LV, first creating a new origin LV,
       then combining it with the existing cache pool named
       by the --cachepool arg (variant, infers --type cache).

       lvcreate -L|--size Size[m|UNIT] --cachepool LV_cachepool VG
           [ -l|--extents Number[PERCENT] ]
           [ -H|--cache ]
           [ -c|--chunksize Size[k|UNIT] ]
           [ -i|--stripes Number ]
           [ -I|--stripesize Size[k|UNIT] ]
           [    --type cache ]
           [    --cachemode writethrough|writeback|passthrough ]
           [    --cachepolicy String ]
           [    --cachesettings String ]
           [    --cachemetadataformat auto|1|2 ]
           [ COMMON_OPTIONS ]
           [ PV ... ]
       -

       Create a cache LV, first creating a new origin LV,
       then combining it with the existing cache pool named
       in the first arg (variant, also use --cachepool).

       lvcreate --type cache -L|--size Size[m|UNIT] LV_cachepool
           [ -l|--extents Number[PERCENT] ]
           [ -H|--cache ]
           [ -c|--chunksize Size[k|UNIT] ]
           [ -i|--stripes Number ]
           [ -I|--stripesize Size[k|UNIT] ]
           [    --poolmetadatasize Size[m|UNIT] ]
           [    --poolmetadataspare y|n ]
           [    --cachemode writethrough|writeback|passthrough ]
           [    --cachepolicy String ]
           [    --cachesettings String ]
           [    --cachemetadataformat auto|1|2 ]
           [ COMMON_OPTIONS ]
           [ PV ... ]
       -

       When LV is a cache pool, create a cache LV,
       first creating a new origin LV, then combining it with
       the existing cache pool named in the first arg
       (variant, infers --type cache, also use --cachepool).
       When LV is not a cache pool, convert the specified LV
       to type cache after creating a new cache pool LV to use
       (use lvconvert).

       lvcreate -H|--cache -L|--size Size[m|UNIT] LV
           [ -l|--extents Number[PERCENT] ]
           [ -c|--chunksize Size[k|UNIT] ]
           [ -i|--stripes Number ]
           [ -I|--stripesize Size[k|UNIT] ]
           [    --cachemode writethrough|writeback|passthrough ]
           [    --cachepolicy String ]
           [    --cachesettings String ]
           [    --cachemetadataformat auto|1|2 ]
           [    --poolmetadatasize Size[m|UNIT] ]
           [    --poolmetadataspare y|n ]
           [ COMMON_OPTIONS ]
           [ PV ... ]
       -

EXAMPLES
       Create  a striped LV with 3 stripes, a stripe size of 8KiB and a
       size of 100MiB.  The LV name is chosen by lvcreate.
       lvcreate -i 3 -I 8 -L 100m vg00

       Create a raid1 LV with two images, and a  useable  size  of  500
       MiB.  This  operation  requires two devices, one for each mirror
       image. RAID metadata (superblock and bitmap) is also included on
       the two devices.
       lvcreate --type raid1 -m1 -L 500m -n mylv vg00

       Create  a  mirror  LV with two images, and a useable size of 500
       MiB.  This operation requires  three  devices:  two  for  mirror
       images and one for a disk log.
       lvcreate --type mirror -m1 -L 500m -n mylv vg00

       Create a mirror LV with 2 images, and a useable size of 500 MiB.
       This operation requires 2 devices because the log is in memory.
       lvcreate --type mirror -m1 --mirrorlog core -L 500m -n mylv vg00

       Create a copy-on-write snapshot of an LV:
       lvcreate --snapshot --size 100m --name mysnap vg00/mylv

       Create a copy-on-write snapshot with a size sufficient for over‐
       writing 20% of the size of the original LV.
       lvcreate -s -l 20%ORIGIN -n mysnap vg00/mylv

       Create  a sparse LV with 1TiB of virtual space, and actual space
       just under 100MiB.
       lvcreate --snapshot --virtualsize 1t  --size  100m  --name  mylv
       vg00

       Create a linear LV with a usable size of 64MiB on specific phys‐
       ical extents.
       lvcreate -L 64m -n mylv vg00 /dev/sda:0-7 /dev/sdb:0-7

       Create a RAID5 LV with a usable  size  of  5GiB,  3  stripes,  a
       stripe  size of 64KiB, using a total of 4 devices (including one
       for parity).
       lvcreate --type raid5 -L 5G -i 3 -I 64 -n mylv vg00

       Create a RAID5 LV using all of the free  space  in  the  VG  and
       spanning  all the PVs in the VG (note that the command will fail
       if there are more than 8 PVs in the VG, in which case -i 7  must
       be  used  to  get  to the current maximum of 8 devices including
       parity for RaidLVs).
       lvcreate --config allocation/raid_stripe_all_devices=1
              --type raid5 -l 100%FREE -n mylv vg00

       Create RAID10 LV with a usable size of 5GiB,  using  2  stripes,
       each  on  a two-image mirror. (Note that the -i and -m arguments
       behave differently: -i specifies the total  number  of  stripes,
       but  -m  specifies the number of images in addition to the first
       image).
       lvcreate --type raid10 -L 5G -i 2 -m 1 -n mylv vg00

       Create a 1TiB thin LV, first creating a new thin  pool  for  it,
       where  the  thin pool has 100MiB of space, uses 2 stripes, has a
       64KiB stripe size, and 256KiB chunk size.
       lvcreate --type thin --name mylv --thinpool mypool
              -V 1t -L 100m -i 2 -I 64 -c 256 vg00

       Create a thin snapshot of a thin LV (the size option must not be
       used, otherwise a copy-on-write snapshot would be created).
       lvcreate --snapshot --name mysnap vg00/thinvol

       Create  a thin snapshot of the read-only inactive LV named "ori‐
       gin" which becomes an external origin for the thin snapshot LV.
       lvcreate --snapshot --name mysnap --thinpool mypool vg00/origin

       Create a cache pool from a fast physical device. The cache  pool
       can then be used to cache an LV.
       lvcreate --type cache-pool -L 1G -n my_cpool vg00 /dev/fast1

       Create  a  cache  LV,  first  creating a new origin LV on a slow
       physical device, then combining the new origin LV with an exist‐
       ing cache pool.
       lvcreate --type cache --cachepool my_cpool
              -L 100G -n mylv vg00 /dev/slow1

SEE ALSO
       lvm(8) lvm.conf(5) lvmconfig(8)

       pvchange(8)  pvck(8)  pvcreate(8)  pvdisplay(8)  pvmove(8) pvre‐
       move(8) pvresize(8) pvs(8) pvscan(8)

       vgcfgbackup(8) vgcfgrestore(8) vgchange(8)  vgck(8)  vgcreate(8)
       vgconvert(8)  vgdisplay(8)  vgexport(8)  vgextend(8) vgimport(8)
       vgimportclone(8) vgmerge(8) vgmknodes(8) vgreduce(8) vgremove(8)
       vgrename(8) vgs(8) vgscan(8) vgsplit(8)

       lvcreate(8)  lvchange(8)  lvconvert(8)  lvdisplay(8) lvextend(8)
       lvreduce(8) lvremove(8) lvrename(8) lvresize(8) lvs(8) lvscan(8)

       lvm-fullreport(8)   lvm-lvpoll(8)   lvm2-activation-generator(8)
       blkdeactivate(8) lvmdump(8)

       dmeventd(8)  lvmetad(8)  lvmpolld(8)  lvmlockd(8)  lvmlockctl(8)
       clvmd(8) cmirrord(8) lvmdbusd(8)

       lvmsystemid(7) lvmreport(7) lvmraid(7) lvmthin(7) lvmcache(7)

Red Hat, Inc.   LVM TOOLS 2.02.171(2)-RHEL7 (2017-05-03)    LVCREATE(8)

[root@ftp:/root]
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