NAME¶
vgcreate - create a volume group
SYNOPSIS¶
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]
[
--[vg]metadatacopies]
NumberOfCopies|unmanaged|all]
[
-s|
--physicalextentsize
PhysicalExtentSize[
bBsSkKmMgGtTpPeE]]
[
-t|
--test] [
-v|
--verbose] [
--version] [
PHYSICAL DEVICE OPTIONS ]
VolumeGroupName PhysicalDevicePath
[
PhysicalDevicePath...]
DESCRIPTION¶
vgcreate creates a new volume group called
VolumeGroupName using
the block special device
PhysicalDevicePath.
If
PhysicalDevicePath was not previously configured for LVM with
pvcreate (8), the device will be initialized with the same default
values used with
pvcreate. If non-default
pvcreate values are
desired, they may be given on the commandline with the same options as
pvcreate. See
PHYSICAL DEVICE OPTIONS for available options.
Note that the restore-related options such as --restorefile, --uuid, and
--physicalvolumesize are not available. If a restore operation is needed, use
pvcreate (8) and
vgcfgrestore (8).
OPTIONS¶
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 value 0 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 --pvmetadatacopies
0 as described in pvcreate(8), and/or use
--vgmetadatacopies.
- --vgmetadatacopies
NumberOfCopies|unmanaged|all
- Sets the desired number of metadata copies in the volume
group. If set to a non-zero value, LVM will automatically manage the
'metadataignore' flags on the physical volumes (see pvcreate or
pvchange --metadataignore ) in order to achieve
NumberOfCopies copies of metadata. If set to
unmanaged , LVM will not automatically manage the
'metadataignore' flags. If set to all, LVM will first
clear all of the 'metadataignore' flags on all metadata areas in
the volume group, then set the value to unmanaged.
The vgmetadatacopies option is useful for volume groups
containing large numbers of physical volumes with metadata as it
may be used to minimize metadata read and write overhead.
The default value is unmanaged.
- -s, --physicalextentsize
PhysicalExtentSize[ bBsSkKmMgGtTpPeE]
- 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.
PHYSICAL DEVICE OPTIONS¶
The following options are available for initializing physical devices in the
volume group. These options are further described in the pvcreate man page.
- -f, --force
- -y, --yes
- -Z, --zero y|n
- --labelsector sector
- --metadatasize size
- --pvmetadatacopies copies
- --dataalignment alignment
- --dataalignmentoffset alignment_offset
EXAMPLES¶
To create a volume group named
test_vg using physical volumes
/dev/sdk1, and
/dev/sdl1 with default physical extent size of
4MB:
vgcreate test_vg /dev/sdk1 /dev/sdl1
SEE ALSO¶
lvm(8),
pvdisplay(8),
pvcreate(8),
vgdisplay(8),
vgextend(8),
vgreduce(8),
lvcreate(8),
lvdisplay(8),
lvextend(8),
lvreduce(8)