vgcreate - create a volume group
vgcreate [--addtag Tag] [--alloc
AllocationPolicy] [-A|--autobackup {y|n}]
[-c|--clustered {y|n}] [-d|--debug]
[-h|--help] [-l|--maxlogicalvolumes
MaxLogicalVolumes] [-M|--metadatatypetype]
[-p|--maxphysicalvolumes MaxPhysicalVolumes]
[-s|--physicalextentsize
PhysicalExtentSize[kKmMgGtT]] [-t|--test]
[-v|--verbose] [--version] VolumeGroupName
PhysicalVolumePath [PhysicalVolumePath...]
vgcreate creates a new volume group called VolumeGroupName using
the block special device PhysicalVolumePath previously configured for
LVM with pvcreate(8).
See lvm for common options.
- -c, --clustered {y|n}
- If clustered locking is enabled, this defaults to y indicating that
this Volume Group is shared with other nodes in the cluster.
If the new Volume Group contains only local disks that are not
visible on the other nodes, you must specify
--clustered n. If the cluster infrastructure is
unavailable on a particular node at a particular time, you may still be
able to use such Volume Groups.
- -l, --maxlogicalvolumes MaxLogicalVolumes
- Sets the maximum number of logical volumes allowed in this volume group.
The setting can be changed with vgchange. For volume groups with
metadata in lvm1 format, the limit and default value is 255. If the
metadata uses lvm2 format, the default value is 0 which removes this
restriction: there is then no limit.
- -p, --maxphysicalvolumes
MaxPhysicalVolumes
- Sets the maximum number of physical volumes that can belong to this volume
group. The setting can be changed with vgchange. For volume groups
with metadata in lvm1 format, the limit and default value is 255. If the
metadata uses lvm2 format, the default value is 0 which removes this
restriction: there is then no limit. If you have a large number of
physical volumes in a volume group with metadata in lvm2 format, for tool
performance reasons, you should consider some use of --metadatacopies
0 as described in pvcreate(8).
- -s, --physicalextentsize
PhysicalExtentSize[kKmMgGtT]
- Sets the physical extent size on physical volumes of this volume group. A
size suffix (k for kilobytes up to t for terabytes) is optional, megabytes
is the default if no suffix is present. The default is 4 MB and it must be
at least 1 KB and a power of 2.
Once this value has been set, it is difficult to change it
without recreating the volume group which would involve backing up and
restoring data on any logical volumes. However, if no extents need
moving for the new value to apply, it can be altered using vgchange
-s.
If the volume group metadata uses lvm1 format, extents can
vary in size from 8KB to 16GB and there is a limit of 65534 extents in
each logical volume. The default of 4 MB leads to a maximum logical
volume size of around 256GB.
If the volume group metadata uses lvm2 format those
restrictions do not apply, but having a large number of extents will
slow down the tools but have no impact on I/O performance to the logical
volume. The smallest PE is 1KB.
The 2.4 kernel has a limitation of 2TB per block device.
To create a volume group named test_vg using physical volumes
/dev/hdk1, and /dev/hdl1 with default physical extent size of
4MB:
vgcreate test_vg /dev/sdk1 /dev/sdl1
lvm(8), pvdisplay(8), pvcreate(8), vgdisplay(8),
vgextend(8), vgreduce(8), lvcreate(8),
lvdisplay(8), lvextend(8), lvreduce(8)