Codex

VGCREATE

Section: Maintenance Commands (8)

Updated: LVM TOOLS (2) (2014-09-01)

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NAME

vgcreate --- create a volume group

SYNOPSIS

vgcreate [-addtag Tag] [--alloc AllocationPolicy] [-A|--autobackup {y|n}] [-c|--clustered {y|n}] [--commandprofile ProfileName] [-d|--debug] [-h|--help] [-l|--maxlogicalvolumes MaxLogicalVolumes] [-M|--metadatatype type] [--metadataprofile ProfileName] [-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?(8). If non-default pvcreate values are desired, they may be given on the commandline with the same options as pvcreate?(8). 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?(8) 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?(8). 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.:
[vg]metadatacopies 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?(8) 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.:
--metadataprofile ProfileName
Uses and attaches the ProfileName configuration profile to the volume group metadata. Whenever the volume group is processed next time, the profile is automatically applied. The profile is inherited by all logical volumes in the volume group unless the logical volume itself has its own profile attached. See (5) for more information about metadata profiles.:
-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 value must be at least 1 sector for LVM2 format (where the sector size is the largest sector size of the PVs currently used in the VG) or 8KiB for LVM1 format and it must be a power of 2. The default is 4 MiB.

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 8KiB to 16GiB and there is a limit of 65534 extents in each logical volume. The default of 4 MiB leads to a maximum logical volume size of around 256GiB.

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 1KiB

The 2.4 kernel has a limitation of 2TiB 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?(8) man page.

:-f, --force

:-y, --yes

:-Z, --zero {y|n}

:--labelsector sector

:--metadatasize size

:--pvmetadatacopies copies

:--dataalignment alignment

:--dataalignmentoffset alignment_offset

Examples

Creates a volume group named "test_vg" using physical volumes "/dev/sdk1" and "/dev/sdl1" with default physical extent size of 4MiB:

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)


Index

NAME

SYNOPSIS

DESCRIPTION

OPTIONS

PHYSICAL DEVICE OPTIONS

Examples

SEE ALSO