LVCREATE(8) | System Manager's Manual | LVCREATE(8) |
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[%{VG|PVS|FREE}] |
-L|--size LogicalVolumeSize[kKmMgGtT]} [-M|--persistent y|n] [--minor minor]
[-m|--mirrors Mirrors [--nosync] [--mirrorlog {disk|core}] [--corelog]
[-R|--regionsize MirrorLogRegionSize]] [-n|--name LogicalVolumeName]
[-p|--permission r|rw] [-r|--readahead ReadAheadSectors|auto|none]
[-t|--test] [-v|--verbose] [-Z|--zero y|n] VolumeGroupName
[PhysicalVolumePath...]
lvcreate {-l|--extents LogicalExtentsNumber[%{VG|FREE}] |
-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.
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.
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.
The optional argument --corelog is equivalent to --mirrorlog core.
Warning: trying to mount an unzeroed logical volume can cause the system to hang.
"lvcreate -i 3 -I 8 -L 100M 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 -m1 -L 500M vg00" tries to create a mirror logical volume with 2 sides with a useable size of 500 MiB. This operation would require 3 devices - two for the mirror devices and one for the disk log.
"lvcreate -m1 --mirrorlog core -L 500M vg00" tries to create 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 --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)
LVM TOOLS 2.02.44-cvs (02-17-09) | Sistina Software UK |