Create Volume Group Wizard: Name and configure volume group

Use this page to specify a name for the volume group and to specify properties for the volume group.

Fields

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Volume group name
Specify a name for the volume group that is unique to the cluster and that is the same across cluster nodes. The name you specify must consist of 1 to 15 characters. You can use alphabetic characters of A - Z and a - z, numbers of 0 - 9, and the underscore (_), minus sign (-), and period (.) characters.
Note: If you do not specify a name, the wizard selects a unique name in the form vg[nn], where [nn] are numeric characters. These numeric characters are selected incrementally based on any currently existing volume group names in this format. For example, the wizard might select a name of vg00 for the first volume group followed by vg01 for the next volume group, and so on.
Volume group type
Select the type of volume group you want to create:
Original
Select this type to allow the volume group to be varied online for more than one AIX® instance at a time. This option is the default value.
Scalable
Select this type to allow the volume group to accommodate up to 1024 physical volumes, up to 256 logical volumes, and up to 32,768 physical partitions. This option, as well as other configuration properties, is not available if you assigned the volume group to a resource group with a startup policy of Online On All Available Nodes.
Big
Select this type to allow the volume group to accommodate up to 128 physical volumes and 512 logical volumes.
Physical partition size (MB)
Select or specify the size of each physical partition in megabytes.

For a volume group type of scalable, select or specify a value of 1 - 131072 that is equal to a power of 2. For all other volume group types, select or specify a value of 1 - 1024 that is equal to a power of 2.

If the volume group contains a physical volume that is larger than 4.064 GB, you must select or specify a physical partition size that is greater than 4 MB. The default physical partition size is 4 MB.

Maximum physical partitions (units of 1024)
Select or specify the maximum number of physical partitions that the volume group can accommodate. Valid values are 32, 64, 128, 256, 512 768, 1024, and 2048. You can set this value only for scalable volume groups. The default value is 32 (32,768 partitions).
Maximum logical volumes
Select or specify the number of logical volumes that can be created for the volume group. Valid values are 256, 512, 1024, 2048, and 4096. You can set this value only for scalable volume groups. The default value is 256.
Enable fast disk takeover or concurrent access
Select the enhanced concurrent mode properties that you want to assign to the volume group.
Note: You cannot select any of these configuration options for the volume group if you assigned it to a resource group on the prior page. The only exception is if you assigned it to a resource group that has a startup policy of Online On All Available Nodes. If you assigned it to such a resource group, the Concurrent access option is the default value, which you can change only to the Critical concurrent access value.
start of changeFast disk takeoverend of change
Select this value to create a volume group that uses enhanced concurrent mode. You must choose this value to allow the disks in the volume group to be used for disk heartbeat. A heartbeat is a signal that one entity sends to another to convey that it is still active. Any shared disk in an enhanced concurrent mode volume group can support a point-to-point heartbeat connection. Each disk can support one connection between two nodes. The connection uses the shared disk hardware as the communication path.

This value also provides for fast disk takeover for the volume group by PowerHA® SystemMirror. During fast disk takeover, PowerHA SystemMirror skips extra processing steps needed to take over the volume group in the case of a node failure. As a result, the fast disk takeover method for enhanced concurrent volume groups is faster than the disk takeover method for standard volume groups.

Concurrent access
Select this value to create a volume group that uses enhanced concurrent mode. This option is the default value if you assigned the volume group to a resource group that has a startup policy of Online On All Available Nodes.
Critical concurrent access
start of changeSelect this option to mark the volume group as critical for high availability for concurrent access. end of change
Enable mirror pools
start of changeSelect whether to enable mirror pools for the volume group. You can set this value only for scalable volume groups. If you select Yes, you must also specify a name for at least two mirror pools.

start of changeA mirror pool is made up of one or more physical volumes. Each physical volume can only belong to one mirror pool at a time. Therefore, mirror pools make it possible to divide the physical volumes of a volume group into separate pools and they provide the ability to restrict the disks that a logical volume copy can use. end of change

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start of changeEnable strict mirror poolsend of change
start of changeSpecifies the mirror pool strictness policy for the volume group, which is set to superstrict for all volume groups. This setting requires the use of mirror pools on each logical volume in the volume group. Partitions allocated for one mirror pool cannot share a physical volume with the partitions from another mirror pool. Consequently, all shared disks for the volume group that you select on the next page of this wizard are included in a mirror pool. Additionally, PowerHA SystemMirror enforces the use of mirror pools to be superstrict. Therefore, you must specify the names for a minimum of two mirror pools and a maximum of three mirror pools in the volume group.end of change
start of changeMirror pool 1 nameend of change
start of changeMirror pool 2 nameend of change
start of changeMirror pool 3 nameend of change
start of changeSpecify a name that is unique to the volume group for each mirror pool to create. You must specify a name for at least two mirror pools. The name you specify must consist of 1 - 15 alphanumeric characters. You can use alphabetic characters of A - Z, a - z, and numbers of 0 - 9. This setting is available only if you select Yes for the Enable mirror pools property.end of change
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