lvcreate(8) -- Linux man page



lvcreate - create a logical volume in an existing volume group  


lvcreate [--addtag Tag] [--alloc AllocationPolicy] [-A/--autobackup y/n] [-C/--contiguous y/n] [-d/--debug] [-h/-?/--help] [-i/--stripes Stripes [-I/--stripesize StripeSize]] {-l/--extents LogicalExtentsNumber |
 -L/--size LogicalVolumeSize[kKmMgGtT]} [-M/--persistent y/n] [--minor minor] [-n/--name LogicalVolumeName] [-p/--permission r/rw] [-r/--readahead ReadAheadSectors] [-t/--test] [-v/--verbose] [-Z/--zero y/n] VolumeGroupName [PhysicalVolumePath...]

lvcreate {-l/--extents LogicalExtentsNumber |
 -L/--size LogicalVolumeSize[kKmMgGtT]} [-c/--chunksize ChunkSize] -s/--snapshot -n/--name SnapshotLogicalVolumeName OriginalLogicalVolumePath  


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) ).
The second form supports the creation of snapshot logical volumes which keep the contents of the original logical volume for backup purposes.  


See lvm for common options.
-c, --chunksize ChunkSize
Power of 2 chunk size for the snapshot logical volume between 4k and 512k.
-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.
-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)
-l, --extents LogicalExtentsNumber
Gives the number of logical extents to allocate for the new logical volume.
-L, --size LogicalVolumeSize[kKmMgGtT]
Gives the size to allocate for the new logical volume. A size suffix of K for kilobytes, M for megabytes, G for gigabytes or T for terabytes 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.
-n, --name LogicalVolumeName
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.
-p, --permission r/w
Set access permissions to read only or read and write.
Default is read and write.
-r, --readahead ReadAheadSectors
Set read ahead sector count of this logical volume to a value between 2 and 120. Ignored by device-mapper.
-s, --snapshot
Create 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. The snapshot 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 lvdisplay(8) on the snapshot in order to check how much data is allocated to it.
-Z, --zero y/n
Controls zeroing of the first KB of data in the new logical volume.
Default is yes.

Warning: trying to mount an unzeroed logical volume can cause the system to hang.



"lvcreate -i 3 -I 8 -L 100 vg00" tries to create 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 --size 100m --snapshot --name snap /dev/vg00/lvol1"
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.



lvm(8), vgcreate(8), lvremove(8), lvrename(8) lvextend(8), lvreduce(8), lvdisplay(8), lvscan(8)