HP XP7 Storage - Manual (Page 88)

You detect and re-create lost updates by checking database log files and other current information
at the local site.
Design your recovery plan so that detection and retrieval of lost updates is performed after the
application is started at the remote site. The detection and retrieval process can take some time.
Prepare for file and database recovery using files for file recovery (for example, database log files
that have been verified as current).
Remote copy and disaster recovery procedures are inherently complex. Consult your HP account
team about recovery procedures.
Switching host operations to the remote site
These procedures apply to single Cnt Ac-J pairs and Cnt Ac-J systems with multiple primary and/or
secondary XP7 systems.
The first recovery task is to switch host operations to the remote site using the RAID Manager
horctakeover command.
•
The horctakeover command checks the pair status of S-VOLs and splits journals. Splitting the
pairs in the journals ensures consistency and usability in the S-VOLs.
•
The horctakeover command attempts to resynchronize pairs to reverse P-VOLs and S-VOLs.
•
If the horctakeover command runs successfully, host operations are taken over by the remote
site using the S-VOLs. For detailed information about RAID Manager and horctakeover, see
HP XP7 RAID Manager User Guide.
Reversing copy direction from remote to local sites
When host operations have been switched to the remote site, restore the local site and re-establish
the Cnt Ac-J system from remote to local sites.
1.
Restore the primary system and data paths.
2. Bring up the host servers at the local site.
3. Make sure that all Cnt Ac-J components are operational.
4. Do all of the following, as applicable:
1.
At the local site, locate P-VOLs whose status is COPY or PAIR. Locate corresponding
S-VOLs at the remote site whose status is SSWS, which indicates that data is being written
to the S-VOLs. At the local site, split these pairs.
2. At the local site, locate P-VOLs whose status is other than unpaired. Locate corresponding
S-VOLs at the remote site whose status is unpaired. At the local site, release the pairs.
3. At the local site, locate pairs whose status is unpaired. At the remote site, release the
pairs.
5. On pairs that were split and in which S-VOL status is now SSWS, run the pairresync -swaps
command. This reverses P-VOLs and S-VOLs and resynchronizes the pairs. The replication is
from remote site to original local site.
NOTE: When you run the pairresync -swaps command, you can use the -d option to specify
a data volume. However, the command is rejected if the restore journal where the data volume
belongs is in Active, Halting, or Stopping status.
6. For S-VOLs whose status is unpaired, recreate the Cnt Ac-J pairs specifying the S-VOLs as
P-VOLs. This creates pairs in which P-VOLs and S-VOLs are reversed.
7. Verify that pair status of all new S-VOLs (which were originally P-VOLs) changes from COPY
to PAIR. When the pair status is changed to PAIR, initial copy operations are finished and
consistency is maintained.
Data in the remote site is now reflected on the local site.
88 Cnt Ac-J disaster recovery operations