Building Disaster Recovery Serviceguard Solutions Using Metrocluster with Continuous Access for P9000 and XP A.11.00

8. Enable the package on all nodes in the primary cluster.
9. Start the package on its primary node in the primary cluster.
Recovering the latest data from DC3
Recovering the latest data from DC3, as described in Step 6 above, guarantees that before the
packages are run on DC1, the latest data from DC3 is replicated on to DC1. The process for this
may vary depending on whether the 3DC configuration uses either Multi-hop Bi-Link configuration
or Multi-target Bi-Link configuration or Tri-Link configuration. The next section lists the required
commands to perform this process, which correspond to both the configurations, and are relevant
only to the recovery process of the latest data from DC3 to DC1.
MULTI-HOP-BI-LINK Data Recovery from DC3 to DC1
The following describes the process to restart a package back to DC1 after the package fails over
to DC3:
1. Log on to any node at DC2 and perform the following:
a. Check the pair status of the dg12 device group:
# pairvolchk -g dg12 -s
b. If the local dg12 volume is in PVOL or SVOL-SSWS.
# pairsplit -g dg12
Go to Step 2
Or
c. If local dg12 volume is other than PVOL or SVOL-SSWS perform a SVOL takeover to
make the local volume SVOL-SSWS or PVOL
# horctakeover -g dg12 -S
# pairsplit -g dg12
d. If the above command fails, then split the pair to SMPL state.
# pairsplit -g dg12 –S
2. Resync data from DC3 to DC2.
Log onto any node at DC2. Resync Journal device group to get the latest data from DC3 to
DC2.
a. Check the pair status of dg23 (DC3 side).
# pairvolchk -g dg23 -s -c
b. If dg23 (DC3 side) is in PVOL.
# pairresync -g dg23
Or
If dg23 (DC3 side) is in SVOL-SSWS.
# pairresync -g dg23 -c 15 -swapp
c. Wait for PAIR state to come up for the Journal device group.
# pairevtwait -g dg23 -t 300 -s pair
d. Swap the role of Journal device group between DC2 and DC3
# horctakeover -g dg23 -t 360
e. Wait for the Journal device group to attain the PAIR state.
# pairevtwait -g dg23 -t 300 -s pair
146 Designing a Three Data Center Disaster Recovery Solution