HP StorageWorks XP Cluster Extension Software Administrator Guide (T1656-96035, April 2010)

and the XP firmware fully support delta resynchronization; however, the delta between the primary
and secondary disks can be large enough for the copy process to exceed the service or resource
group startup timeout value.
• The ResyncWaitTimeout object can cause the resource to fail if its value is higher than the resource
startup timeout value.
• If running in fence-level ASYNC, the default value of AsyncTakeoverTimeout can cause the resource
to fail if its value is set beyond the recommended startup timeout value. This is done because the
takeover process for fence-level ASYNC can take longer when communication links are slow.
To prevent the takeover timeout from terminating the takeover commands, measure the time required
to copy the installed XP disk array cache and adjust the resource startup timeout interval. When
measuring the copy time, measure only the slowest link used for XP Continuous Access Software.
This ensures that the XP disk array cache can be transferred from the remote XP disk array, even
in the event of a single surviving replication link between the XP disk arrays.
NOTE:
Because the failover environment is dispersed over two or more data centers, the failover time cannot
be expected to be the same as that of a single data center with a single shared disk device. Therefore,
you must adjust the service or resource group startup timeout value and the monitor interval of the
XP RAID Manager device group based on failover tests you perform to verify the proper configuration
setup.
Configuring XP Cluster Extension for Linux110