Administration Guide › Managing CA VM:Director in a Single System Image Complex › Disk Space Management in an SSI Complex

Disk Space Management in an SSI Complex

Disk space in an SSI complex is shared and accessible from every member system. However, you can configure certain volumes to be accessible from only one member. Any minidisk defined in a SUBCONFIG entry can be accessed only from within the member system where that SUBCONFIG is active.

We recommend that you separate shared volumes and unshared volumes for minidisk allocation. One method to accomplish the separation is to use separate allocation POOLs. For example, you could perform the following configurations:

• One or more pools for shared volumes
• One pool per member system for the volumes which are dedicated for use by that member

We recommend that you configure the product Servant Facility feature to simplify SSI operation. The product server is able to launch a servant virtual machine in any member node. The product server can then format or copy the minidisks that are defined within SUBCONFIG entries. For more information, see “Servant Facility in an SSI Complex.”

If the servant facility is not in use issue the following kinds of commands from the member node that has access to the minidisk:

• Commands that include long running operations, such as FORMAT, COPYFILE, or DDR processes
• Commands that operate on nonshared minidisks

The SSI environment does not allow any operation which involves the parallel use of two minidisks defined in SUBCONFIG directory entries for different member systems. For example, you cannot use a command like DUPMDISK to duplicate a minidisk in one SUBCONFIG to another SUBCONFIG on a different member. To accommodate this restriction, you can perform the following procedure:

1. Duplicate a nonshared minidisk to a shared minidisk.
2. Duplicate the shared minidisk to a new unshared minidisk.
3. Remove the intermediate shared minidisk.