LVCREATE(8)LVCREATE(8)NAMElvcreate - create a logical volume in an existing volume group
SYNOPSISlvcreate [--addtag Tag] [--alloc AllocationPolicy] [-a|--available
{y|n|ey|en|ly|ln}] [-A|--autobackup {y|n}] [-C|--contiguous {y|n}]
[-d|--debug] [-h|-?|--help] [--noudevsync] [--ignoremonitoring] [--mon‐
itor {y|n}] [-i|--stripes Stripes [-I|--stripesize StripeSize]]
{[-l|--extents LogicalExtentsNumber[%{VG|PVS|FREE}] | -L|--size Logi‐
calVolumeSize[bBsSkKmMgGtTpPeE]] | -V|--virtualsize Virtual‐
Size[bBsSkKmMgGtTpPeE]} [-M|--persistent {y|n}] [--minor minor]
[-m|--mirrors Mirrors [--nosync] [--mirrorlog {disk|core|mirrored} |
--corelog] [-R|--regionsize MirrorLogRegionSize]] [-n|--name Logi‐
calVolume{Name|Path}] [-p|--permission {r|rw}] [-r|--readahead {ReadA‐
headSectors|auto|none}] [-t|--test] [-T|--thin [-c|--chunksize Chunk‐
Size] [--poolmetadatasize MetadataSize[bBsSkKmMgG]]] [--thinpool Thin‐
PoolLogicalVolume{Name|Path}] [--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] [--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 phys‐
ical 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 spec‐
ify 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, --available {y|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 automatically (-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 clustered lock‐
ing is enabled, -aey will activate exclusively on one node and
-aly will activate only on the local node.
-c, --chunksize ChunkSize
Power of 2 chunk size in sector units (512b). For snapshot log‐
ical volume the value must be between 8 (4KB) and 1024 (512KB)
and the default value is 8. For thin pool logical volume the
value must be between 128 (64KB) and 2097152 (1MB) and the
default value is 128.
-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.
-i, --stripes Stripes
Gives the number of stripes. This is equal to the number of
physical volumes to scatter the logical volume.
-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.
-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 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.
--minor minor
Set the minor number.
-M, --persistent {y|n}
Set to y to make the minor number specified persistent.
-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 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.
The optional argument --mirrorlog specifies the type of log to
be used. 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 again each
time the device is activated, for example, after every reboot.
Using "mirrored" will create a persistent log that is itself
mirrored.
The optional argument --corelog is equivalent to --mirrorlog
core.
-n, --name LogicalVolume{Name|Path}
The name for the new logical volume.
Without this option a default names of "lvol#" will be generated
where # is the LVM internal number of the logical volume.
--noudevsync
Disable 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.
--monitor {y|n}
Start or avoid monitoring a mirrored or snapshot logical volume
with dmeventd, if it is installed. If a device used by a moni‐
tored mirror reports an I/O error, the failure is handled
according to mirror_image_fault_policy and mirror_log_fault_pol‐
icy set in lvm.conf.
--ignoremonitoring
Make no attempt to interact with dmeventd unless --monitor is
specified.
-p, --permission {r|rw}
Set access permissions to read only or read and write.
Default is read and write.
--poolmetadatasize MetadataSize[bBsSkKmMgG]
Set the size of thin pool's metadata logical volume. Supported
value is in range between 2MiB and 16GiB. Default value is
(Pool_LV_size / Pool_LV_chunk_size * 64b). Default unit is
megabytes.
-r, --readahead {ReadAheadSectors|auto|none}
Set 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
A mirror is divided into regions of this size (in MB), and the
mirror log uses this granularity to track which regions are in
sync.
-s, --snapshot OriginalLogicalVolume{Name|Path}
Create 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 snapshot with the specified size does not need
the same amount of storage the origin has. In a typical sce‐
nario, 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 lvdisplay(8) on the snap‐
shot in order to check how much data is allocated to it. Note
that 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
the rate at which the snapshot data is growing so you can avoid
running out of space.
-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. "raid5", "mirror", "snapshot", "thin", "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",
"zero", "raid1", "raid4", "raid5", or "raid6".
-V, --virtualsize VirtualSize[bBsSkKmMgGtTpPeE]
Create a sparse device of the given size (in MB 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.
-Z, --zero {y|n}
Controls zeroing of the first KB of data in the new logical vol‐
ume.
Default is yes.
Volume will not be zeroed if 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 stripesize of 8KB
and a size of 100MB 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 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 1TB with space
for just under 100MB 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 100MiB pool logical volume for thin provisioning build with 2
stripes 64KiB and chunk size 128KiB 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
SEE ALSOlvm(8), vgcreate(8), lvremove(8), lvrename(8)lvextend(8), lvreduce(8),
lvdisplay(8), lvscan(8)Sistina Software UK LVM TOOLS 2.02.95(2) (2012-03-06) LVCREATE(8)
