HP 3PAR StoreServ Cluster Extension Software Administrator Guide

Timing considerations for Windows Clustering (MSFC)
HP 3PAR StoreServ Cluster Extension gives priority to storage system operations over cluster software
operations. If HP 3PAR StoreServ Cluster Extension is invoked during a virtual volume
synchronization/full synchronization operation, or is gathering information about the remote storage
system, it waits until the requested status information is reported. This ensures the priority of data
integrity over cluster software failover behavior. However, this behavior can cause a failure of HP
3PAR StoreServ Cluster Extension resources in some cases:
• When HP 3PAR StoreServ Cluster Extension communicates with the HP 3PAR StoreServ Storage,
online operations could time out depending on the settings of the command time out
configuration.
• When a virtual volume resynchronization/ full synchronization is in progress, the software
waits until the Remote Copy volume group is in a synced state if the ApplicationStartup
resource property is set to RESYNCWAIT. In case of resynchronization, the delta between the
source and destination virtual volume could be large enough for the resynchronization process
to exceed the resource PendingTimeout value.
• The values of the ResyncWaitTimeout properties must be less than the configured resource
PendingTimeout value.
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 that in a single data center with a single shared
disk device. Therefore, the following values of the HP 3PAR StoreServ Cluster Extension resource
and the service or application using that resource, must be adjusted, based on failover tests
performed to verify the proper configuration setup: FailoverPeriod, RestartPeriod,
PendingTimeout, LookAlive, and IsAlive.
In addition, FailoverPeriod value of the service or application must be higher than the
RestartPeriod value of the resource and both must be higher than the resource's
PendingTimeout value. Microsoft Cluster provides two properties to adjust state change
recognition or resolution:
• IsAlive
• LookAlive
NOTE: For Windows Server 2003/2008/2008 R2/2012/2012 R2, the IsAlive and
LookAlive properties are replaced by the Thorough Resource Health Check Interval
and Basic Resource Health Check Interval properties.
Bouncing service or application
HP 3PAR StoreServ Cluster Extension will alternate (start and fail) between local nodes if the
ApplicationStartup property has been set to FASTFAILBACK and no remote system is
available until the service or application restart limit has been reached.
Creating array password file
HP 3PAR StoreServ Cluster Extension uses HP 3PAR CLI commands to manage the HP 3PAR
StoreServ Storage objects. HP 3PAR CLI can be installed on the client machine to manage the HP
3PAR StoreServ Storage remotely. Each CLI session requires a user name and an encrypted
password for successful command execution. Alternatively, a onetime password file can be
generated for subsequent use. Generated password file is specific to the HP 3PAR StoreServ
Storage. However, it can be copied to other systems for use. HP 3PAR StoreServ Cluster extension
requires this password file for its operations. For each array managed by HP 3PAR StoreServ
Cluster Extension, appropriate password files must be generated and configured during the HP
3PAR StoreServ Cluster Extension configuration.
Timing considerations for Windows Clustering (MSFC) 51