Manual Reference Pages  - VGCHANGE (8)


vgchange - change attributes of a volume group


See Also


vgchange [--addtag Tag] [--alloc AllocationPolicy] [-A|--autobackup {y|n}] [-a|--available [e|l] {y|n}] [--monitor {y|n}] [--poll {y|n}] [-c|--clustered {y|n}] [-u|--uuid] [-d|--debug] [--deltag Tag] [-h|--help] [--ignorelockingfailure] [--ignoremonitoring] [--sysinit] [--noudevsync] [-l|--logicalvolume MaxLogicalVolumes] [-p|--maxphysicalvolumes MaxPhysicalVolumes] [--[vg]metadatacopies] NumberOfCopies|unmanaged|all] [-P|--partial] [-s|--physicalextentsize PhysicalExtentSize[bBsSkKmMgGtTpPeE]] [--refresh] [-t|--test] [-v|--verbose] [--version] [-x|--resizeable {y|n}] [VolumeGroupName...]


vgchange allows you to change the attributes of one or more volume groups. Its main purpose is to activate and deactivate VolumeGroupName, or all volume groups if none is specified. Only active volume groups are subject to changes and allow access to their logical volumes. [Not yet implemented: During volume group activation, if vgchange recognizes snapshot logical volumes which were dropped because they ran out of space, it displays a message informing the administrator that such snapshots should be removed (see lvremove(8)). ]


See lvm for common options.
-A, --autobackup {y|n}
  Controls automatic backup of metadata after the change. See vgcfgbackup (8). Default is yes.
-a, --available [e|l]{y|n}
  Controls the availability of the logical volumes in the volume group for input/output. In other words, makes the logical volumes known/unknown to the kernel.
If clustered locking is enabled, add ’e’ to activate/deactivate exclusively on one node or ’l’ to activate/deactivate only on the local node. Logical volumes with single-host snapshots are always activated exclusively because they can only be used on one node at once.
-c, --clustered {y|n}
  If clustered locking is enabled, this indicates whether this Volume Group is shared with other nodes in the cluster or whether it contains only local disks that are not visible on the other nodes. If the cluster infrastructure is unavailable on a particular node at a particular time, you may still be able to use Volume Groups that are not marked as clustered.
-u, --uuid
  Generate new random UUID for specified Volume Groups.
--monitor {y|n}
  Start or stop monitoring a mirrored or snapshot logical volume with dmeventd, if it is installed. If a device used by a monitored mirror reports an I/O error, the failure is handled according to mirror_image_fault_policy and mirror_log_fault_policy set in lvm.conf(5).
--poll {y|n}
  Without polling a logical volume’s backgrounded transformation process will never complete. If there is an incomplete pvmove or lvconvert (for example, on rebooting after a crash), use --poll y to restart the process from its last checkpoint. However, it may not be appropriate to immediately poll a logical volume when it is activated, use --poll n to defer and then --poll y to restart the process.
  Indicates that vgchange(8) is being invoked from early system initialisation scripts (e.g. rc.sysinit or an initrd), before writeable filesystems are available. As such, some functionality needs to be disabled and this option acts as a shortcut which selects an appropriate set of options. Currently this is equivalent to using --ignorelockingfailure, --ignoremonitoring, --poll n and setting LVM_SUPPRESS_LOCKING_FAILURE_MESSAGES environment variable.
  Disable udev synchronisation. The process will not wait for notification from udev. It will continue irrespective of any possible udev processing in the background. You should only use this if udev is not running or has rules that ignore the devices LVM2 creates.
  Make no attempt to interact with dmeventd unless --monitor is specified. Do not use this if dmeventd is already monitoring a device.
-l, --logicalvolume MaxLogicalVolumes
  Changes the maximum logical volume number of an existing inactive volume group.
-p, --maxphysicalvolumes MaxPhysicalVolumes
  Changes the maximum number of physical volumes that can belong to this volume group. For volume groups with metadata in lvm1 format, the limit 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 pvchange or pvcreate --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.
-s, --physicalextentsize PhysicalExtentSize[bBsSkKmMgGtTpPeE]
  Changes 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.

Before increasing the physical extent size, you might need to use lvresize, pvresize and/or pvmove so that everything fits. For example, every contiguous range of extents used in a logical volume must start and end on an extent boundary.

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.

  If any logical volume in the volume group is active, reload its metadata. This is not necessary in normal operation, but may be useful if something has gone wrong or if you’re doing clustering manually without a clustered lock manager.
-x, --resizeable {y|n}
  Enables or disables the extension/reduction of this volume group with/by physical volumes.


To activate all known volume groups in the system:

\       vgchange -a y

To change the maximum number of logical volumes of inactive volume group vg00 to 128.

\       vgchange -l 128 /dev/vg00


lvchange(8), lvm(8), vgcreate(8)

Sistina Software UK VGCHANGE (8) LVM TOOLS 2.02.84(2)-RHEL5 (2011-08-26)
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