Creating SI pairs

Creating SI pair copies the P-VOL to the S-VOL.

SI pair creation might be rejected if the Unmap command operation is in progress with system option mode 905 ON. Wait a while and then retry the operation. If the operation still fails, set system option mode 905 to OFF and retry again.

Prerequisites:

The P-VOL and S-VOL are unpaired.

If the P-VOL is already paired with other S-VOLs ("PAIR" status), you have determined that the status of existing S-VOLs is the status that is required to create the new pair.

For more information about S-VOL status, see Unaffected S-VOL status and pair user tasks.

If you are concerned with host server I/O performance, make sure that the I/O load is light.

You must set the same T10 PI attribute value for both the P-VOL and S-VOL.

Procedure

In Command Suite:

On the Resources tab, click Storage Systems, expand the storage system tree, right-click the target storage system, and then select Local Replication.

In Device Manager - Storage Navigator:

In the Explorer pane, click Storage Systems, expand the storage system tree, and then click Replication > Local Replication.

Select the SI Pairs tab.

In the SI Pairs tab, click Create SI Pairs.

In the Select Pair Configuration window of the Create SI Pairs wizard, complete the following and then click Next:

For Copy Type, select ShadowImage.

For Pair Topology Type, select the pair topologies that match your configuration.

For more information about creating L1 and L2 pairs with different topologies, see Creating L1 and L2 pairs with different topologies.

For Split Type, select how you want to split the pair.

Values:

- Non Split: The pair is not split.

If you are simultaneously creating an L1 pair and an L2 pair, to prevent a failure and splitting the L2 pair before the pair is split ("PSUS" status), select Non Split.

- Quick Split: Splits the new pair and then copies the data so that the S-VOL is immediately available for read and write I/O. The storage system copies the remaining differential data to the S-VOL in the background.

- Steady Split: Copies the differential data to the S-VOL and then splits the new pair.

Default: Quick Split

For Copy Pace, select the rate at which you want the storage system to copy data.

Values:

- Slower: Improved host server I/O performance but slower processing speed.

- Medium: Average processing speed and host server I/O performance.

- Faster: Faster processing speed but slower host server I/O performance.

Processing speed and host server I/O performance are affected by the pace you select.

In the Select Primary Volumes window of the Create SI Pairs wizard, complete the following:

In the Available LDEVs table, select the LDEV you want to be the P-VOL and then click Add.

You can filter LDEV by Port ID, Host Group Name or iSCSI Target Alias.

The LDEV is moved to the Selected LDEVs table.

Click Next.

In the Select Secondary Volumes window of the Create SI Pairs wizard, assign LDEVs as S-VOL to the specified P-VOL LDEV (or LDEVs). Complete the following and then click Finish:

If you specified one P-VOL, select a secondary LDEV from the Available LDEVs table, and click Set. Repeat this step to assign additional S-VOLs.

If you specified multiple P-VOLs, select an LDEV from the Available LDEVs table and then select a P-VOL LDEV from the Selected Pairs table, and click Set. Repeat this step as many times as needed to make all your pairings.

If you do not select a P-VOL from the Selected Pairs table, the S-VOL you select and set is assigned to P-VOLs in the order they are listed in the table.

(Optional) To sort the Available LDEVs and Selected Pairs tables according to the capacity, for Capacity, choose a capacity item by which to sort the tables.

The remaining number you have to select refers to the P-VOLs that do not have an assigned S-VOL, as seen in the Selected Pairs table.

(Optional) To select LDEVs to be displayed in the Available LDEVs table by each port ID, host group name or iSCSI target alias, choose from Port ID, Host Group Name or iSCSI target alias.

(Optional) To sort the Selected Pairs table, click Sort in the middle-left.

(Optional) To change the split type and the rate at which data is copied, which applies to all new pairs, change the pair options.

For more information about changing pair options, see Changing SI pair options.

(Optional) To change MU numbers, do the following:

a. Select the line for the LDEV in the Selected Pairs table.

b. Click Edit Mirror Units.

c. In the Edit Mirror Units dialog box, specify the S-VOL's L1 and L2 mirror unit numbers, and click OK.

The pair topology is modified.

For more information about changing a pair's topology, see Creating L1 and L2 pairs with different topologies.

(Optional) Change the pair options.

For more information about changing pair options, see Changing SI pair options.

(Optional) To remove an unwanted LDEV or pair from the Selected Pairs table, select the line for the LDEV or pair you want to remove and click Remove.

The pair's topology is refined.

In the Confirm window of the Create SI Pairs wizard, complete the following and then click Apply. The setting is queued as a task and performed in order.

For Task Name, type a name for the task.

Default: date-window name

Character and symbol limit: 32 alphanumeric except / : , ; * ? “ < > |

Case sensitive: Yes

For Go to tasks window for status, select to open the Tasks window.

The SI pair is created and the status is "PAIR".

Open the Tasks window to verify the result of the operation. A task can be suspended or canceled if the processing of the task is not started.