LVCREATE(8)LVCREATE(8)NAMElvcreate - create a logical volume in an existing volume group
SYNOPSISlvcreate [--addtag Tag] [--alloc AllocationPolicy] [-a|--activate
[a|e|l]{y|n}] [-k|--setactivationskip {y|n}] [-K|--ignoreactivation‐
skip] [-A|--autobackup {y|n}] [-C|--contiguous {y|n}] [-d|--debug]
[-h|-?|--help] [--noudevsync] [--ignoremonitoring] [--monitor {y|n}]
[--[raid]maxrecoveryrate Rate] [--[raid]minrecoveryrate Rate]
[-i|--stripes Stripes [-I|--stripesize StripeSize]] {[-l|--extents Log‐
icalExtentsNumber[%{VG|PVS|FREE}] | -L|--size LogicalVolume‐
Size[bBsSkKmMgGtTpPeE]] | -V|--virtualsize VirtualSize[bBsSkKmMg‐
GtTpPeE]} [-M|--persistent {y|n}] [--minor minor] [-m|--mirrors Mirrors
[--nosync] [--mirrorlog {disk|core|mirrored} | --corelog] [-R|--region‐
size MirrorLogRegionSize]] [-n|--name LogicalVolume{Name|Path}]
[-p|--permission {r|rw}] [-r|--readahead {ReadAheadSectors|auto|none}]
[-t|--test] [-T|--thin [-c|--chunksize ChunkSize[bBsSkKmMgG]] [--dis‐
cards {ignore|nopassdown|passdown}] [--poolmetadatasize MetadataVolume‐
Size[bBsSkKmMgG]] [--poolmetadataspare {y|n}]] [--thinpool ThinPoolLog‐
icalVolume{Name|Path} [-s|--snapshot [VolumeGroup{Name|Path}/] Exter‐
nalOriginLogicalVolumeName]] [--type SegmentType] [-v|--verbose]
[-Z|--zero {y|n}] VolumeGroup{Name|Path}[/ThinPoolLogicalVolumeName]
[PhysicalVolumePath[:PE[-PE]]...]
lvcreate [-l|--extents LogicalExtentsNumber[%{VG|FREE|ORIGIN}] |
-L|--size LogicalVolumeSize[bBsSkKmMgGtTpPeE]] [-c|--chunksize Chunk‐
Size[bBsSkK]] [--noudevsync] [--ignoremonitoring] [--monitor {y|n}]
[-n|--name SnapshotLogicalVolume{Name|Path}] -s|--snapshot {[Vol‐
umeGroup{Name|Path}/]OriginalLogicalVolumeName -V|--virtualsize Virtu‐
alSize[bBsSkKmMgGtTpPeE]}
DESCRIPTIONlvcreate creates a new logical volume in a volume group (see vgcre‐
ate(8), vgchange(8)) by allocating logical extents from the free physi‐
cal extent pool of that volume group. If there are not enough free
physical extents then the volume group can be extended (see vgex‐
tend(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 {y|ay|n|ey|en|ly|ln}
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 can only be created in the active state so -an cannot
be used with --snapshot. 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 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.
-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. To activate such volumes, an extra
-K/--ignoreactivationskip option must be used. The flag is not
applied during deactivation. Use lvchange -k/--setactivation‐
skip {y | n} command to attach or detach the 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.
-K, --ignoreactivationskip
Ignore the flag to skip Logical Volumes during activation.
-c, --chunksize ChunkSize[bBsSkKmMgG]
Gives the size of chunk for snapshot and thin pool logical vol‐
umes. Default unit is in kilobytes.
For snapshots the value must be power of 2 between 4KiB and
512KiB and the default value is 4.
For thin pools the value must be between 64KiB and 1GiB and the
default value starts with 64 and scales up to fit the pool meta‐
data size within 128MiB, if the pool metadata size is not speci‐
fied. Thin pool target version <1.4 requires the value to be a
power of 2. The newer target version relaxes limitation to be a
multiple of 64KiB. For target version <1.5 discard is not sup‐
ported for non power of 2 values.
-C, --contiguous {y|n}
Sets or resets the contiguous allocation policy for logical vol‐
umes. Default is no contiguous allocation based on a next free
principle.
--discards {ignore|nopassdown|passdown}
Sets discards behavior for thin pool. Default is passdown.
-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 -i3 would
use 3 devices for striped logical volumes, 4 devices for RAID
4/5, and 5 devices for RAID 6.
-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.
--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 log‐
ical volume. 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 Ori‐
gin Logical Volume with the suffix %ORIGIN.
-L, --size LogicalVolumeSize[bBsSkKmMgGtTpPeE]
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 kilo‐
bytes, M for megabytes, G for gigabytes, T for terabytes, P for
petabytes or E for exabytes is optional.
Default unit is megabytes.
-m, --mirrors Mirrors
Creates a mirrored logical volume with Mirrors copies. For
example, specifying -m1 would result in a mirror with two-sides;
that is, a linear volume plus one copy.
Specifying the optional argument --nosync will cause the cre‐
ation of the mirror to skip the initial resynchronization. Any
data written afterwards will be mirrored, but the original con‐
tents will not be copied. This is useful for skipping a poten‐
tially 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. The
--mirrorlog and --corelog options apply to the "mirror" segment
type only.
The optional argument --mirrorlog specifies the type of log to
be used for logical volumes utilizing the legacy "mirror" seg‐
ment 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 mir‐
ror 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.
When the legacy "mirror" segment type is used, the optional
argument --corelog is equivalent to --mirrorlog core.
-M, --persistent {y|n}
Set to y to make the minor number specified persistent.
--minor minor
Sets the minor number.
--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.
--[raid]maxrecoveryrate Rate[bBsSkKmMgG]
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[bBsSkKmMgG]
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.
--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.
--poolmetadatasize MetadataVolumeSize[bBsSkKmMgG]
Sets the size of thin pool's metadata logical volume. Supported
values are in range between 2MiB and 16GiB. Default value 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 thin pool recovery. Only
one such volume is maintained within a volume group with the
size of the biggest thin metadata volume. Default is yes.
-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 equiv‐
alent to specifying zero.
-R, --regionsize MirrorLogRegionSize
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.
-s, --snapshot OriginalLogicalVolume{Name|Path}
Creates a snapshot logical volume (or snapshot) for an existing,
so called original logical volume (or origin). Snapshots pro‐
vide 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 snap‐
shot 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 grow‐
ing 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.
-T, --thin, --thinpool ThinPoolLogicalVolume{Name|Path}
Creates thin pool or thin logical volume or both. Specifying
the optional argument --size will cause the creation of the thin
pool logical volume. Specifying the optional argument --virtu‐
alsize 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.
Requires device mapper kernel driver for thin provisioning from
kernel 3.2 or newer.
--type SegmentType
Create a logical volume that uses the specified segment type
(e.g. mirror(-m), raid5, snapshot(-s), thin(-T), thin-
pool, ...). Many segment types have a commandline switch alias
that will enable their use (-s is an alias for --type snapshot).
However, this argument must be used when no existing commandline
switch alias is available for the desired type, as is the case
with error, raid1, raid4, raid5, raid6, raid10 or zero.
-V, --virtualsize VirtualSize[bBsSkKmMgGtTpPeE]
Creates a sparse device of the given size (in MiB by default)
using a snapshot or thinly provisioned device when thin pool is
specified. Anything written to the device will be returned when
reading from it. Reading from other areas of the device will
return blocks of zeros. Virtual snapshot is implemented by cre‐
ating 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.
-Z, --zero {y|n}
Controls zeroing of the first KiB of data in the new logical
volume.
Default is yes.
Volume will not be zeroed if the read only flag is set.
Snapshot volumes are zeroed always.
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 vol‐
ume 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 any‐
where ) - 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 /dev/vg00/snap which has access
to the contents of the original logical volume named /dev/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 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 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 vol‐
ume in vg00 that will use an existing thin pool "vg00/pool":
lvcreate-s --thinpool vg00/pool origin
SEE ALSOlvm(8), lvm.conf(5), lvconvert(8), lvchange(8), lvextend(8), lvre‐
duce(8), lvremove(8), lvrename(8)lvs(8), lvscan(8), vgcreate(8)Sistina Software UK LVM TOOLS 2.02.100(2) (2013-08-13) LVCREATE(8)