HP XP P9500 Storage User Manual

Page 108

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Running the YKRESYNC REVERSE results in one of the following conditions:

•

The original copy flow of the primary-remote site pair reverses and flows from the
primary-remote secondary volume to the primary volume.

•

The original copy flow does not reverse because of failure in the primary site or data path.

Depending on the result, proceed as follows:

If the original Cnt Ac-S Z data flow reverses
1.

Re-create the Cnt Ac-J Z pair using the YKMAKE command from the Cnt Ac-S Z primary site
to the Cnt Ac-J Z remote site. This results in a 3DC cascade configuration, with the original
Cnt Ac-S Z S-VOL as the primary volume. See the lower right configuration in

Figure 18 (page

109)

.

2.

Restore the primary site or data path, or both. This must be done before proceeding.

3.

Stop host operations to the Cnt Ac-S Z intermediate site.

4.

Suspend the Cnt Ac-S Z pair using the YKSUSPND FORWARD command.

5.

Resume host operations to the Cnt Ac-S Z S-VOL in the primary site.

6.

Run the YKRESYNC FORWARD command to resume the Cnt Ac-S Z pair with replication again
from the original Cnt Ac-S Z S-VOL in the primary site to the Cnt Ac-S Z S-VOL in the
intermediate site.

The system changes back to the original 3DC multi-target configuration.

If the original Cnt Ac-S Z data flow did not reverse
1.

To back up the data, create a new Cnt Ac-J Z pair using YKMAKE from the Cnt Ac-S Z S-VOL
in the intermediate site to the Cnt Ac-J Z secondary volume in the remote site.See the upper-right
configuration in

Figure 18 (page 109)

.

2.

Restore the primary site or data path, or both. This must be done before proceeding.

3.

Release the Cnt Ac-J Z pair using the YKDELETE command.

4.

Resynchronize the Cnt Ac-S Z pair using the YKRESYNC command to start the replication to
the primary site.

5.

Release the current Cnt Ac-J pair, which extends between the Cnt Ac-S secondary site and the
Cnt Ac-J Z secondary site.

6.

Stop host operations at the Cnt Ac-S Z intermediate site.

7.

Suspend the Cnt Ac-S Z pair using the YKSUSPND FORWARD command.

8.

Resume host operations to the primary site Cnt Ac-S Z volume.

9.

Resynchronize the Cnt Ac-S Z pair from the primary site using the YKRESYNC FORWARD
command. Replication is again from the original Cnt Ac-S Z S-VOL to the original S-VOL.

10. Re-create the Cnt Ac-J Z pair from the primary site to the remote site using the YKMAKE

command. The system is now changed back to the original 3DC multi-target configuration.

108 Disaster recovery operations

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