Creating Thin Image pairs

You can create an HTI pair and define the pair in a consistency group. You can create a maximum of 1,024 HTI pairs at the same time. To create more than 1,024 HTI pairs, repeat this task.

You specify the pool to be used for the HTI pair when you create the pair. An HTI pair consists of a P-VOL and up to 1,024 S-VOLs. The MU numbers are assigned in the order of 3 to 1,023, followed by 0 to 2.

The P-VOL and S-VOLs you select must be the same size if you create an HTI pair with an S-VOL specified. If you select a P-VOL that you are already using as the P-VOL for another HTI pair, you must specify the same pool for both pairs. For example, if you specify three S-VOLs for one P-VOL, specify the same pool for the three HTI pairs.

 After creating an HTI pair, the number of pairs shown in the summary section in the Local Replication window and the number of pairs shown in the list in the TI Primary Volumes tab can be different. Wait until the configuration information has completed processing. If the numbers of pairs do not match, reload the configuration information (see Reloading configuration information).

 To prevent the HTI pair from being suspended (“PSUE” status), do not create HTI pairs while you are shutting down the storage system.

Prerequisites

• You have the Storage Administrator (Local Copy) role.

• If you are sharing SI volumes with HTI volumes, the SI pair exists.

• To use an SI volume as an HTI P-VOL when an available MU number does not exist, you have completed the following:

1. Deleted the HTI pairs of MU numbers 0 to 2.

2. Created the SI pair.

3. Recreated the HTI pair with an MU number of 3 or greater assigned.

1. Navigate to the Local Replication window.

In Hitachi Command Suite:

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

2. Right-click the target storage system, and then select Local Replication.

In Device Manager - Storage Navigator:

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

2. In the Local Replication window, select a P-VOL in the TI Primary Volumes tab or a snapshot group in the Snapshot Groups tab, and then click Create TI Pairs.

3. In Use Primary Volumes of Thin Image Pairs, select Yes or No.

For Yes, continue to the next step. For No, complete the following:

1. From the Available Primary Volumes table, select the LDEV you want to assign as the P-VOL.

- A nondisruptive migration volume will not appear in the Available Primary Volumes table.

2. Click Select Pool button.

3. In the Select Pool window, select pool from Available pools table.

4. Click OK.

4. For Snapshot Group, select either Create New to assign the pair to a new snapshot group, or Use Existing to assign it to an existing snapshot group. You must assign an HTI pair to a snapshot group when creating it.

Complete one of the following:

- For Create New, enter values for Number of Snapshot Data per Primary Volume, Prefix, and Initial number, and then select Snapshot Group Configuration.

- For Use Existing, select Snapshot Group Configuration, and then select the snapshot group to which you want to assign the pair from the Available Snapshot Groups table. If you select All, enter a value in Number of Snapshot Data per Primary Volume.

 To create pairs and assign the pairs to a snapshot group using the CCI, see Creating Thin Image pairs and defining them in snapshot or consistency groups using the CCI.

5. Click Add.

The selected LDEV is moved to the Selected Primary Volumes table.

6. Click NEXT.

7. From the Available LDEVs table, select the LDEV you want to assign as the S-VOL and then click Set.

The selected LDEV is displayed in the Secondary Volumes column of the Selected Pairs table.

• A nondisruptive migration volume will not appear in the Available LDEVs table.

• If you select a capacity in Capacity, the Available LDEVs and Selected Pairs tables display the LDEVs that match the selected capacity.

• If you select a row in the Available LDEVs table and a row in the Selected Pairs table and then click Set, you can configure a pair.

• If you select LDEVs which were assigned to an S-VOL with the Exclude Assigned Volumes check box unchecked, the S-VOL to which snapshot data is assigned can be changed.

8. Click Finish.

9. 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.

10. Click Apply.

The task is registered, and if the Go to tasks window for status check box was selected, the Tasks window appears.

Related topics

• Creating Thin Image pairs and defining them in snapshot or consistency groups using the CCI.

• Workflow for creating Thin Image pairs using Device Manager - Storage Navigator.

• Workflow for accelerating the pair deletion process.

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