Using the failoverpprc and failbackpprc commands

This scenario describes how to use the failoverpprc and failbackpprc DS CLI commands. It does not cover all situations or functions for which these commands can be used. The example uses 4 multiple pairs and it is presumed that your volume relationships are set up as site A to site B or A-->B.

The use of the these two DS CLI commands is associated with recovering data from a planned or unplanned outage of data processing. The failoverpprc command is generally used first and it must complete its process before you can use the failbackpprc command.

To perform the failoverppc process, you must issue the command against your volumes in the order in which you have them. In other words, if you have your original remote mirror and copy pairs set up as A --> B, you must issue the failoverpprc with your volumes in A:B order.

Note: This process differs from the way that was was done on a 2105 whether using the ESS CLI commands or the Specialist.

The following is a description of what these two commands accomplish.

failoverpprc: This command changes the secondary device into a primary suspended device while leaving the primary device in its current state. After you issue this command, the configuration is symmetrical with both devices being primaries. You can issue the failbackpprc command to resume mirroring in either direction.
failbackpprc: This command can be issued against any remote mirror and copy volume that is in a primary suspended state. The command copies the required data from the source volume to the target volume in order to resume mirroring. The command is usually used after a failoverpprc command has been issued to restart mirroring either in the reverse direction (recovery site to production site) or original direction (production site to recovery site). However, this command also works if the target volume has been made simplex or is a secondary volume. The command performs a full or partial copy as required.

Issue your failoverpprc with your volumes in A:B order. Your command could look like this:

dscli>failoverpprc -dev IBM.1750-75FA120 -remotedev IBM.1750-75FA150
 0100:0100 0101:0101  0102:0102 0103:0103

Wait for the command to fully process. B is in a primary suspended state.
Issue the failbackpprc command so that B becomes your primary and A becomes your new secondary. Your command could look like this:
```
dscli>failbackpprc -dev IBM.1750-75FA120 -remotedev IBM.1750-75FA150
 0100:0100 0101:0101  0102:0102 0103:0103
```
Start your applications on your server at Site B. To get back to your original pairings, proceed as follows after site A is recovered.
Issue the failoverpprc command to failover B:A. This makes A primary suspended.
Wait for the command to fully complete.
Issue the failbackpprc command to failback B:A. This restores your pairs back to their original relationships.