Provided by: lvm2_2.02.133-1ubuntu10_amd64 
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)
Sistina Software UK LVM TOOLS 2.02.133(2) (2015-10-30) LVCREATE(8)