Creating a concurrent volume group on cluster nodes using C-SPOC

Using C-SPOC simplifies the procedure for creating a concurrent volume group on selected cluster nodes.

About this task

For creating a concurrent volume path on VPATH disks, see Managing data path devices with C-SPOC. If you add a VPATH disk to a volume group made up of hdisks, the volume group will be converted to VPATHs on all nodes.

All disk devices are properly attached to the cluster nodes.
All disk devices are properly configured on all cluster nodes and listed as available on all nodes.
The cluster concurrent logical volume manager is installed.
All disks that will be part of the volume group are concurrent capable.

To create a concurrent volume group for a selected list of cluster nodes:

Procedure

From the command line, enter smit cspoc.
In SMIT, select Storage > Volume Groups > Create a Volume Group (or Create a Volume Group with Data Path Devices) and press Enter.
SMIT displays a list of cluster nodes.
Select one or more nodes from the list of cluster nodes and press Enter.
The system correlates a list of all free concurrent-capable physical disks that are available to all nodes selected. (Free disks are those disks that currently are not part of a volume group and have PVIDs.) SMIT displays the list of free physical disks in a multi-picklist by PVIDs. If you are creating a volume group with data path devices, only disks capable of hosting them will be listed.
Select one or more PVIDs from the list and press Enter.
SMIT displays the cl_mkvg panel with a major number inserted into the Major Number data field. The system determines this free major number; do not change it.

Enter field values as follows:

Table 1. PVID fields
Field	Value
Node Names	Names of the selected nodes are displayed.
PVID	PVID of the selected disk.
VOLUME GROUP name	The name of the volume group must be unique within the cluster and distinct from the service IP address and resource group names; it should relate to the application it serves, as well as to any corresponding device. For example, `websphere_service_VG`. If you do not provide a name, a unique name will be generated.
Physical partition SIZE in megabytes	Accept the default.
Volume Group MAJOR NUMBER	The system displays the number C-SPOC has determined to be correct. Important: If you change the volume group major number, the command might not be able to run on a node that does not have that major number currently available. Check for a commonly available major number on all nodes before changing this setting.
Enable Fast Disk Takeover or Concurrent Access	Select Concurrent Access. An enhanced concurrent mode volume group is created. If a resource group was created, it is created with the policies online on all available nodes and never fall back.
Volume Group Type	Displays the type of volume group. You cannot change this field.
CRITICAL volume group	Select yes to identify this volume group as a critical volume group. When a volume work is identified as a critical volume group, you can configure the volume group by using the Manage Critical Volume Groups option. This setting determines how PowerHA® SystemMirror® responds when it cannot access the volume group.

Results

C-SPOC verifies communication paths and version compatibility and then runs the command on all the nodes you selected.

Note: If the major number entered on the SMIT panel was not free at the time that the system attempted to make the volume group the command will display an error for the node that did not complete the execution and continue to the other nodes. At the completion of the command the volume group will not be active on any node in cluster.