Designing Disaster Recovery Clusters using Metroclusters and Continentalclusters, Reprinted October 2011 (5900-1881)

Takeover Timeout (for third data center)
When a package is being failed over to the third data center (SVOL of the Continuous Access-Journal
device group), the Metrocluster toolkit script issues takeover command on the SVOL. If the journal
group pair is flushing the journal data from its PVOL to SVOL and takeover timeout occurs, the
following situations would happen:
1. The device group pair state remains in PVOL-PAIR/SVOL-PAIR
2. The journal data continues transferring to the SVOL
In this case, you must wait for the completion of the journal data flushing and the Continuous
Access-Journal pair state to be:
• Hot-standby site: PVOL-PAIR or PVOL-PSUS(E)
• Third site: SVOL-PSUS(SSWS) or SVOL-PSUE(SSWS)
Either 1) use FORCEFLAG to startup the package on third site or 2) fix the problem (if any of
Continuous Access links was failed) and resume the data replication with the following procedures:
1. Split the Continuous Access-Journal device group pair completely (pairsplit -g <dg>-S>
2. Re-create a Continuous Access-Journal pair from it’s original PVOL as source. (use the
paircreate command)
NOTE: You can specify “none” as the copy mode for initial copy operations. If the none mode
is selected, full copy operations are not performed. The user is responsible for using the none mode
only when the user is sure that data in the primary data volume is exactly the same as data in the
secondary data volume.
Continuous Access-Journal Device Group PVOL-PAIR with SVOL-PSUS(SSWS) State
PVOL-PAIR with SVOL-PSUS(SSWS)is an intermediate state. It could happen, but is unlikely to be
seen. The state PVOL-PAIR/SVOL-SSWS is an invalid state for P9000 or XP Continuous Access
Journal. In this state, if you issue a pairresync or takeover command, it would fail. It is necessary
to wait for the PVOL to become PSUE or PSUS.
Additional Reading
The following documents contain additional useful information:
• Managing Serviceguard Nineteenth Edition (5900-1492)
• Understanding and Designing Serviceguard Disaster Tolerant Architectures (B7660-90018)
• Designing Disaster Tolerant HA Clusters Using Metrocluster and Continentalclusters
(5900–1484)
• Use the following URL to access HP’s High Availability web page:
http://www.hp.com/go/hpux-ha-monitoring-docs
• Use the following URL for access to a wide variety of HP-UX documentation:
http://www.hp.com/
To learn more about P9000 or HP StorageWorks XP disk arrays, contact your local HP storage
representative.
474 Designing a Three Data Center Disaster Recovery Solution