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Commands Reference, Volume 6

varyonvg Command


Activates a volume group.


varyonvg [ -b ] [ -c ] [ -f ] [ -n ] [ -p ] [ -r ] [ -s ] [ -t ] [ -u ] VolumeGroup


The varyonvg command activates the volume group specified by the VolumeGroup parameter and all associated logical volumes. A volume group that is activated is available for use. When a volume group is activated, physical partitions are synchronized if they are not current.

A list of all physical volumes with their status is displayed to standard output whenever there is some discrepancy between the Device Configuration Database and the information stored in the Logical Volume Manager. The volume group may or may not be varied on. You must carefully examine the list and take proper action depending on each reported status to preserve your system integrity.

While varying on in concurrent mode, if the varyon process detects that there are logical volumes which are not previously known to the system, their definitions are imported. The permissions and ownership of the new device special files are duplicated to those of the volume group special file. If you have changed the permissions and/or ownership of the device special files of the logical volume on the node it was created, you will need to perform the same changes on this node.

If the volume group cannot be varied on due to a loss of the majority of physical volumes, a list of all physical volumes with their status is displayed. To varyon the volume group in this situation, you will need to use the force option.

The varyonvg will fail to varyon the volume group if a majority of the physical volumes are not accessible (no Quorum). This condition is true even if the quorum checking is disabled. Disabling the quorum checking will only ensure that the volume group stays varied on even in the case of loss of quorum.

The volume group will not varyon if there are any physical volumes in PV_MISSING state and the quorum checking is disabled. This condition is true even if there are a quorum of disks available. To varyon on in this situation either use the force option or set an environment variable MISSINGPV_VARYON to TRUE (set this value in /etc/environment if the volume group needs to be varied with missing disks at the boot time).

In the above cases (using force varyon option and using MISSINGPV_VARYON variable), you take full responsibility for the volume group integrity.

Note: To use this command, you must either have root user authority or be a member of the system group.

You can use the System Management Interface Tool (SMIT) to run this command. To use SMIT, enter:

smit varyonvg


-b Breaks disk reservations on disks locked as a result of a normal varyonvg command. Use this flag on a volume group that is already varied on. This flag only applies to AIX 4.2 or later.

  • This flag unlocks all disks in a given volume group.
  • The -b flag opens the disks in the volume group using SC_FORCED_OPEN flag. For SCSI and FC disks this forces open all luns on the target address that this disk resides on. Volume Groups should therefore not share target addresses when using this varyon option.
-c Varies the volume group on in concurrent mode or Enhanced Concurrent mode. This is only possible if the volume group is Concurrent Capable or Enhanced Concurrent Capable and the system has the HACAMP product loaded and available. If neither is true, the volume group fails the varyon.

If the varyon process detects that there is a new logical volume in the volume group whose name is already being used for one of the existing logical volumes, then the varyon fails. You will need to rename the existing logical volume before attempting the varyon again.

  1. Enhanced Concurrent volume groups use Group Services. Group Services ships with HACMP ES and must be configured prior to activating a volume group in this mode.
  2. Only Enhanced Concurrent Capable volume groups are supported when running with a 64 bit kernel. Concurrent Capable volume groups are not supported when running with a 64 bit kernel.
-f Allows a volume group to be made active that does not currently have a quorum of available disks. All disk that cannot be brought to an active state will be put in a removed state. At least one disk must be available for use in the volume group.
-n Disables the synchronization of the stale physical partitions within the VolumeGroup.
-p All physical volumes must be available to use the varyonvg command.
-r Varies on the volume group in read-only mode. This mode prevents:
  • Write operations to logical volumes
  • LVM meta-data updates
  • Stale partitions synchronization

Note: All LVM high-level commands that require the LVM meta-data update will fail the request in this mode.
-s Makes the volume group available in System Management mode only. Logical volume commands can operate on the volume group, but no logical volumes can be opened for input or output.

Note: Logical volume commands also cannot read or write to or from logical volumes in a volume group varied on with the -s flag. Logical volumes that attempt to write to a logical volume in a volume group varied on with the -s flag (such as chvg or mklvcopy) may display error messages indicating that they were unable to write to and/or read from the logical volume.
-t Checks the timestamps in the Device Configuration Database and the Logical Volume Manager. If there is a discrepancy in the timestamps, the synclvodm command is issued to synchronize the database.
This check is always done if the Volume Group is varied on in concurrent mode.
-u Varies on a volume group, but leaves the disks that make up the volume group in an unlocked state. Use this flag as part of the initial varyon of a dormant volume group. This flag only applies to AIX 4.2 or later.

Attention: The base design of LVM assumes that only one initiator can access a volume group. The HACMP product does work with LVM in order to synchronize multi-node accesses of a shared volume group. However, multi-initiator nodes can easily access a volume group with the -b and -u flags without the use of HACMP. Your must be aware that volume group status information may be compromised or inexplicably altered as a result of disk protect (locking) being bypassed with these two flags. If you use the -b and -u flags, data and status output cannot be guaranteed to be consistent.


  1. To activate volume group vg03, enter:

    varyonvg vg03
  2. To activate volume group vg03 without synchronizing partitions that are not current, enter:

    varyonvg -n vg03


/usr/sbin Contains the varyonvg command directory.
/tmp Stores the temporary files while the command is running.

Related Information

The chvg command, lspv command, lslv command, lsvg command, varyoffvg command.

The System Management Interface Tool in AIX 5L Version 5.2 System Management Concepts: Operating System and Devices explains the structure, main menus, and tasks that are done with SMIT.

The Logical Volumes in AIX 5L Version 5.2 System Management Concepts: Operating System and Devices explains the Logical Volume Manager, physical volumes, logical volumes, volume groups, organization, ensuring data integrity, and allocation characteristics.

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