Depending on the MP unit assignment settings on the storage system, automatic volume allocation might occur when adding a controller chassis (CBX) pair. Automatic volume allocation is performed upon CBX pair addition on the controller board (CTL) with the MP unit assignment settings enabled. To suppress automatic allocation, disable the MP unit assignment settings. You can verify the MP unit assignment settings on the storage system by using the raidcom get system -key mpu command. To change the settings, use the raidcom modify system command.
The following table shows the ownership settings based on types of volumes or volume groups when adding CBX pairs.
| Volume type (including a volume group) | Advanced setting for ownership |
|---|---|
| Journal group | The ownership is set individually for the entire system including expanded packages. |
| Journal volume | The ownership is set according to the ownership of the associated journal group. |
|
V-VOL (DP-VOL) |
|
| Pool-VOL | The same ownerships are set for the modules in the parity group. |
| Internal volume that is not a pool-VOL | |
| External volume | The ownership is set according to the one of the external volume group. |
The following restrictions apply when a CBX pair is added on the storage system that uses a pool:
- See Configuration with parity groups containing multiple CBX pairs in Pool-VOL requirements.
- To distribute the load on the newly added CBX pair, move pages from the existing CBX pair to the additional CBX pair. Use the following procedures to move pages to the additional CBX pair.