Expanding the existing pool capacity

Use this procedure to add CBX pairs by expanding the pool capacity. This procedure includes setting SOMs 1106 and 1195. Contact customer support for assistance.

Rebalancing with SOMs 1106 and 1195 set to ON is required.

• If the rebalancing with SOMs 1106 and 1195 is not performed, accessing the additional CBX pair volume (DP-VOL 2) causes data transfer to the existing CBX pair (CBX pair 1), and then that temporarily increases the total load on the storage system.
• Reasons for setting SOM 1195 to ON:

  When SOM 1195 is OFF in a pool that contains only SSD parity groups and no external volumes, pages do not move across CBX pairs to perform rebalance. Set SOM 1195 to ON.

• Reasons for setting SOM 1106 to ON:

  If pages are reclaimed by performing zero data page reclamation on V-VOLs, perform rebalance.

  When SOM 1106 is OFF, do not perform rebalance if pages are not reclaimed by performing zero data page reclamation. Set SOM 1106 to ON to perform rebalance even if the pages are not reclaimed.

• You can verify the processing status of rebalancing by using the raidcom get pool -key basic command. Verify that the value for D_PM displays the following:
  • WRB: Waiting for rebalance
  • RB: Rebalancing in progress

  You can verify the progress percentage of rebalancing by referring to D_PM (%). When rebalancing is complete, D_PM displays N indicating that no pool operation is in progress.

The estimated rebalancing time for 10 TB is 80 hours. Depending on the drive type and the RAID level, however, it might be shorter or longer than the expected time. If you want to estimate the rebalance completion time, periodically check D_PM (%) displayed in the output of the raidcom get pool -key basic command. Based on the change in D_PM (%) and the time required for that change, calculate the estimated rebalancing completion time.