HP StorageWorks XP Remote Web Console Software - Manual (Page 135)

Continuous Access XP Journal user guide 135
1. Identify the journal groups and data volumes containing important files and data for disaster recovery.
2. For Command View XP, install the management station. For Command View XP or XP Remote Web
Console, install Continuous Access XP Journal hardware and software, and establish Continuous
Access XP Journal operations for the journal groups and data volumes identified in step 1 .
3. Establish file and database recovery procedures. These procedures should already be established for
recovering data volumes that become inaccessible due to some failure.
4. Install and configure host failover software between the primary and secondary sites.
File and database recovery procedures
When the primary or secondary disk array suspends a Continuous Access XP Journal pair due to a
disaster, the secondary data volume might contain in-process data. A data set could be open or
transactions might not have completed. Therefore, you must establish file recovery procedures. These
procedures should be the same as those used for recovering data volume that becomes inaccessible due to
control unit failure.
Continuous Access XP Journal does not provide procedures for detecting and retrieving lost updates. To
detect and recreate lost updates, you must check other current information (for example, database log file)
that was active at the primary site when the disaster occurred. Since this detection/retrieval process can
take a while, your disaster recovery scenario should be designed so that detection/retrieval of lost updates
is performed after the application has started at the secondary site.
To prepare for file and database recovery, use the files for file recovery (for example, database log files
that have been verified as current).
IMPORTANT: Remote copy and disaster recovery procedures are inherently complex. Consult your
HP account support representative on recovery procedures.
NOTE: See ” Power management for disk arrays and network relay devices ” on page 143 for information
on recovering a pinned track on a Continuous Access XP Journal volume.
Switching operations to the secondary site
If a disaster or failure occurs at the primary site, the first disaster recovery activity is to switch your
operations to the secondary site. Executing the RAID Manager
horctakeover
command on Continuous
Access XP Journal pairs enables your business tasks to be taken over to the secondary site, using
secondary data volumes in the secondary site. The
horctakeover
command checks the pair status of
secondary data volumes and splits journal groups that will become a Continuous Access XP Journal pair.
This ensures consistency of secondary data volumes and makes the secondary data volumes usable. If
possible, the
horctakeover
command attempts to restore pairs to reverse primary and secondary data
volumes. If the
horctakeover
command executes successfully, your business tasks will be taken over to
(or your business application will be started at) the secondary site, using secondary data volumes.
Transferring operations back to the primary site
After the disaster recovery procedure is finished and your business applications are running at the
secondary site, the next activity is to restore the primary site and make arrangements for copying data from
the secondary site back to the primary site. The following procedures explains how to use RAID Manager
to copy data from the secondary site to the primary site.
1. Restore the primary disk array and remote copy connections, bring up the host servers at the primary
site, and ensure that all Continuous Access XP Journal components are fully operational.
2. At the primary site, locate primary data volumes whose pair status is COPY or PAIR, and locate
corresponding secondary data volumes whose pair status is SSWS. If such volume pairs are found,
issue a request for splitting the pairs to the primary data volumes.
3. At the primary site, locate primary data volumes whose pair status is not SMPL, and locate
corresponding secondary data volumes whose pair status is SMPL. If such volume pairs are found,
issue a request for deleting the pairs to the primary data volumes.