Changing options used by mirrors

Most pair operations are performed on multiple pairs. This is done using a journal or mirrors. You can change the following options that affect the pairs in a mirror:

• Path Watch Time: the interval from the time a path becomes blocked to the time when the mirror is suspended.

• Path Watch Time Transfer: forwards the master journal’s Path Watch Time value to the restore journal.

• Copy Pace: the pace at which data is copied.

• Transfer Speed: the speed for data transfer.

• Delta Resync Failure: the processing that takes place in the event of a failure.

Before you begin

• Mirror options can be changed on both primary and secondary storage systems.

• To change mirror options, the status of the mirror must be one of the following:

• Initial

• Active

• Stopped

• Hold

• Holding

• Hold(Failure)

• The Transfer Speed option can be changed if the mirror’s status is Active, Hold, or Holding. When the status is Holding, the option can only be changed from the primary storage system.

• When changing options for multiple mirrors, a changed value is applied to all the mirrors. On the other hand, leave the options unchanged that you do not want to change.

Procedure

1. Open the Remote Replication window:

In Command Suite:

1. On the Resources tab, expand the Storage Systems tree.

2. Right-click the target storage system, and click Remote Replication.

In Device Manager - Storage Navigator:

1. In the Explorer pane, expand the Storage Systems tree.

2. Expand the target storage system tree, expand Replication, and click Remote Replication.

2. In the Mirrors tab, select the mirror whose options you want to change.

3. Click More Actions > Edit Mirror Options.

4. In the Edit Mirror Options window, for Path Watch Time, specify the interval from the time a path becomes blocked to the time when the mirror is suspended. Ranges are from 1 to 59 minutes, 1 to 23 hours, or 1 to 30 days. A numeric value is required.

The interval must be the same for master and restore journals in the same mirror, otherwise the journals suspend at different times. See next step to use this setting for both journals.

Important: If you want a mirror to split immediately after a path becomes blocked, ask customer support to set system option mode 448 to ON and set system option mode 449 to OFF.

5. For Path Watch Time Transfer, specify whether to use the same Path Watch Time value you specified for the master journal for the restore journal. Specify this option in the primary site only.

• Yes: The Path Watch Time value is also used for the restore journal.

For a pair in a delta resync configuration, select Yes in the primary site.

• No (default): The Path Watch Time value is not used for the restore journal.

6. For Copy Pace, specify the pace for initial copy activity per volume. Specify this option in the primary site only.

• Slower is the default.

• If specifying Medium, ensure that write I/O is 10 MB/s or less per parity group. If it exceeds 10 MB/s, pairs may be suspended.

• If specifying Faster, ensure that I/O will not occur. If update I/O occurs, pairs may be suspended.

7. For Transfer Speed, specify data transfer line speed in Mbps (megabits per second). You can specify 256, 100, 10, or 3.

• Use 3 when the transfer speed is 3 to 9 Mbps.

• Use 10 when the transfer speed is 10 to 99 Mbps.

• Use 100 when the transfer speed is 100 to 255 Mbps.

• Use 256 when the transfer speed is 256 Mbps or higher.

 This setting does not affect master journals unless the CCI horctakeover command is used to change a master journal into a restore journal.

8. For Delta Resync Failure, specify the processing that takes place when the delta resync operation cannot be performed. Specify this option in the primary site only.

- Entire Copy (default): the entire P-VOL is copied to the S-VOL. Use Entire if your journals are part of a multiple-journal configuration in a CCI consistency group.

- No Copy: No processing occurs: the S-VOL is not updated.

9. Click Finish.

10. In the Confirm window, review the settings and enter a task name in the Task Name box.

11. Click Apply to save your settings to the system.