HP 3PAR Cluster Extension Software Administrator Guide (5697-0925, May 2011)

clx3PARrun, use the HP 3PAR Management Console GUI or CLI to check the progress of
syncing.
• Depending on the amount of data that is out of sync between the source and destination virtual
volumes while the Remote Copy link(s) is unavailable, a resynchronization or a complete copy
operation is initiated when the Remote Copy link(s) is re-established. The amount of delta data
to be transferred between the source and destination virtual volume could be large enough
for the copy process to take some time.
• To prevent the failover timeout trigger from terminating a failover command before it is finished,
the time to copy an average amount of daily processed (write) data should be measured and
the resource online timeout interval should be adjusted accordingly. Use only one (the slowest)
link used for Remote Copy to measure the copy time. This ensures that the average daily
generated data can be transferred fast enough from the remote HP 3PAR storage system, even
in the event of a single surviving replication link between the HP 3PAR storage systems. In
general, because the failover environment is dispersed into two (or more) data centers, the
failover time cannot be expected to be the same as it would be in a single data center with
a single shared disk device.
Restrictions for customized implementations
The following restrictions apply when using the HP 3PAR Cluster Extension CLI:
• The 3PAR Cluster Extension CLI command clx3PARrun must be invoked before the associated
disk resources are activated on a server.
• Associated disk resources must not be activated on any other system. If other disk resources
are activated, HP 3PAR Cluster Extension may remove write-access rights for those disk devices
(putting them in read-only mode).
Pre-execution and post-execution programs
HP 3PAR Cluster Extension can invoke pre-execution and post-execution programs prior to or after
a HP 3PAR Cluster Extension failover/failback function. These programs can be any executable,
and must be able to provide return codes to HP 3PAR Cluster Extension. If the programs add
significant execution time to the application service startup process, the timeout values for the
startup process must be adjusted in the cluster software.
HP 3PAR Cluster Extension transfers information as CLI arguments to the pre-execution and
post-execution programs. You must not specify CLI arguments. Pre-executables and post-executables
must be specified by full path in the PreExecScript and PostExecScript objects. If no executable is
specified (there is an empty value for the object), no preprocessing or postprocessing is performed.
If the object is not defined, then the argument value is empty.
The following arguments are transferred to the scripts in this order:
1. Resource name
2. DC A HP 3PAR storage system serial number
3. DC B HP 3PAR storage system serial number
4. DC A Remote Copy volume group
5. DC B Remote Copy volume group
6. DC A host (server) names
7. DC B host (server) names
8. Replication mode
9. Local replication role
10. Remote replication role
11. Remote copy link status
12. Failsafe policy
Restrictions for customized implementations 51