User's Guide

NOTE: The preceding steps are automated provided the default value of 1 is being used for the
auto variable AUTO_PSUEPSUS. Once the Continuous Access link failure has been fixed, the user
only needs to halt the package at the failover site and restart on the primary site. However, if you
want to reduce the amount of application downtime, you should manually invoke pairresync
before failback.
Full resynchronization must be manually initiated (as described in the next section) after repairing
the following failures:
• failure of the recovery P9000 or XP disk array for a given application package followed by
application startup on a primary host
• failure of all Continuous Access links with Fence Level NEVER or ASYNC with restart of the
application on a primary host
Pairs must be manually recreated if both the primary and recovery P9000 or XP disk arrays are
in the SMPL (simplex) state.
Make sure you periodically review the following files for messages, warnings and recommended
actions. It is recommended to review these files after system, data center and/or application failures:
• /var/adm/syslog/syslog.log
• /etc/cmcluster/<package-name>/<package-name>.log
• /etc/cmcluster/<bkpackage-name/<bkpackage-name>.log
Using the pairresync Command
The pairresync command can be used with special options after a failover in which the recovery
site has started the application and has processed transaction data on the disk at the recovery site,
but the disks on the primary site are intact. After the Continuous Access link is fixed, depending
on which site you are on, use the pairresync command in one of the following two ways:
• pairresync -swapp—from the primary site.
• pairresync -swaps—from the failover site.
These options take advantage of the fact that the recovery site maintains a bit-map of the modified
data sectors on the recovery array. Either version of the command will swap the personalities of
the volumes, with the PVOL becoming the SVOL and SVOL becoming the PVOL. With the
personalities swapped, any data that has been written to the volume on the failover site (now
PVOL) are then copied back to the SVOL, which is now running on the primary site. During this
time the package continues running on the failover site. After resynchronization is complete, you
can halt the package on the failover site, and restart it on the primary site. Metrocluster will then
swap the personalities between the PVOL and the SVOL, returning PVOL status to the primary site.
Some Further Points
• This toolkit may increase package startup time by 5 minutes or more. Packages with many
disk devices will take longer to start up than those with fewer devices due to the time needed
to get device status from the P9000 or XP disk array or to synchronize.
NOTE: Long delays in package startup time will occur in those situations when recovering
from broken pair affinity.
• The value of RUN_SCRIPT_TIMEOUT in the package ASCII file should be set to NO_TIMEOUT
or to a large enough value to take into consideration the extra startup time due to getting
status from the P9000 or XP disk array. (See the previous paragraph for more information on
the extra startup time).
• Online cluster configuration changes may require a Raid Manager configuration file to be
changed. Whenever the configuration file is changed, the Raid Manager instance must be
Completing and Running a Continentalclusters Solution with Continuous Access P9000 or XP 209