Increasing pool capacity

Adding pool-VOLs to a pool increases, or expands, the pool’s capacity. Check the pool’s available capacity and expand the pool as needed.

Use the following formula to calculate the pool capacity:

Pool capacity = the total capacity of pool-VOLs in the pool - the management area size of the pool-VOL with the system area

Adding pool-VOLs to pools to expand pool capacity moves data to the added space on a per-page basis which rebalances the usage rate among parity groups of the pool-VOLs.

 Moving existing data to the added space on a per-page basis can decrease host I/O performance.

You can add up to 1,024 pool-VOLs (including volumes already in a pool) to a pool.

Prerequisite: You are currently not decreasing the pool capacity.

1. Navigate to the Pools window.

In Hitachi Command Suite:

1. On the Resources tab, click Storage Systems, and then expand the storage system tree.

2. Expand the target storage system, right-click DP Pools, and then select System GUI.

In Device Manager - Storage Navigator:

1. In the Explorer pane, click Storage Systems, and then expand the storage system tree.

2. Click Pools.

2. In the Pools tab in the Pools window, select the check box for the pool to which you want to add a pool-VOL from the list and then click Expand Pool.

 You can only increase the capacity for one pool at a time.

3. In the Expand Pool window of the Expand Pool wizard, click Select Pool VOLs.

4. In the Select Pool VOLs window, complete the following and then click OK:

• (Optional) To filter rows, in the Available Pool Volumes table, select ON in the Filter component.

• (Optional) To select all of the pool-VOLs in the list, in the Available Pool Volumes table, click Select All Pages.

• (Optional) To specify the capacity unit and the number of rows to display, in the Available Pool Volumes table, click Options.

• In the Available Pool Volumes table, select the LDEV you want and then click Add.

The LDEV is moved to the Selected Pool Volumes table.

The Select Pool VOLs window closes.

5. In the Expand Pool window of the Expand Pool wizard, click Finish.

6. In the Confirm window, complete the following.

• Confirm the settings.

• Enter a name for your task in Task Name.

• (Optional) Select Go to tasks window for status if you want the Tasks window to open after you click Apply.

7. Click Apply.

The pool-VOL is added to the pool, and if the Go to tasks window for status check box was selected, the Tasks window appears.

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