Deleting Thin Image pairs

Thin Image User Guide
Version
9.8.6
Audience
anonymous
Part Number
MK-98RD9020-16
Delete Thin Image pairs when you do not need them or when you want to delete snapshot data using the Delete Pairs window in HDvM - SN, or the corresponding CCI command.

When you delete a pair, the P-VOL and the S-VOL change to SMPL(PD) and they are unpaired. When volumes are unpaired, they are not displayed in the main window. After the deletion, you can use the unpaired volumes in other pairs. You cannot create pairs in the SMPL(PD) status, and you cannot allocate an S-VOL to snapshot data, or cancel or change the allocation. To shorten the time in the SMPL(PD) status, delete snapshot data if any, and delete pairs after the pair status changes to PAIR. When you set a snapshot group, if all pairs in a snapshot group are unpaired, the snapshot group is automatically removed. Make sure that the snapshot group is removed before starting another pair task.

All snapshot data in a P-VOL must be deleted for there to be a decrease in the pool usage rate and an increase in unused capacity.

The amount of time required for deletion depends on the following, even if the pair resynchronization rate is 100 percent:

  • The amount of pool capacity a pair is using.
  • The number of pairs being operated concurrently.

The pair synchronization rate shows the rate that S-VOL data matches that of the next generation of the S-VOL. If the S-VOL is the latest one, the synchronization rate is computed by comparing the S-VOL with the P-VOL.

For a Thin Image pair where the cascade attribute is enabled, the information displayed in Synchronization Rate (%) of the View Pair Synchronization Rate window in Device Manager - Storage Navigator, or the information displayed by the raidcom get snapshot command in CCI, varies depending on the pair status. For details, see View Pair Synchronization Rate window.

If you cannot delete Thin Image pairs with Device Manager - Storage Navigator, you can use the raidcom delete snapshot -range tree command to forcibly delete all Thin Image cascaded pairs in a snapshot tree. For details about CCI commands, see Pair tasks using CCI or Device Manager - Storage Navigator and the Command Control Interface Command Reference.

If forcible deletion of all Thin Image pairs in a snapshot tree is not complete 10 minutes after the command is issued, the pair deletion might have been interrupted due to contention with processing of changing storage system configuration. In this case, run the command again to forcibly delete all Thin Image pairs in the snapshot tree.

Note: After deleting a Thin Image pair, the number of pairs shown in the summary section in the Local Replication window and in the list on the TI Root Volumes tab can be different. Wait until the configuration has completed processing. If the numbers do not match, reload the configuration information (see Reloading Thin Image configuration information).
Note: If the amount of snapshot data in selected P-VOLs or the total number of pairs in selected snapshot groups exceeds 37,768, an error message appears when attempting to perform pair tasks.

If you use CCI commands, see Pair tasks using CCI or Device Manager - Storage Navigator.

  • You must have the Storage Administrator (Local Copy) role.
  • The Thin Image pair must be suspended ("PSUE" status), paired ("PAIR" status), or split ("PSUS" status).
  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 Root Volumes tab or a snapshot group in the Snapshot Groups tab.
  3. Click Operate TI Pairs.
  4. In the TI Pairs window, select the pair you want to delete, and then click More Actions > Delete Pairs.
    You can specify P-VOLs in Device Manager - Storage Navigator until the total number of snapshots or clones reaches 32,768. In addition, you can specify snapshot groups until the total number of pairs reaches 32,768. For cascaded pairs with layers, specify pairs at the lowest layer, and then higher layers.
  5. Click Finish, and then confirm the settings.
  6. Accept the default task name or enter a unique name.
    You can enter up to 32 letters, numbers, and symbols, except the following:

    \ / : , ; * ? " < > |

  7. If you want to monitor the task after submitting it, select Go to tasks window for status.
  8. Click Apply to submit the task.
The pair deletion process begins ("SMPL(PD)" status), and then the pair is deleted.
Related tasks