HP 3PAR StoreServ Cluster Extension Software Administrator Guide

clx3PARrun is used in a script or called by another program or 3PAR StoreServ Storage IP
cannot be reached.
• In the UCF.cfg file, if the ApplicationStartup attribute is set to RESYNCWAIT, HP 3PAR
StoreServ Cluster Extension tries to resynchronize virtual volumes and waits until the Remote
Copy volume group is in a synced state. Depending on the amount of data to be transferred,
it could take hours to resynchronize. If this is the case, clx3PARrun may take some time to
return. Do not stop clx3PARrun, use the HP 3PAR StoreServ 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 StoreServ Storage,
even in the event of a single surviving replication link between the HP 3PAR StoreServ Storage.
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 StoreServ Cluster Extension CLI:
• The HP 3PAR StoreServ 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 StoreServ Cluster Extension may remove write-access rights for those
disk devices (putting them in read-only mode).
Cluster Extension Cmdlets for CSV and Virtual Machine Management
The following PowerShell Cmdlets are supported by CLX to perform various operations:
• Add-CSVDependencyOnCLX3PAR
• Add-VMDependencyOnCLX3PAR
• Get-VMOnClusterSharedVolumeListForCLX3PAR
As part of the CLX installation, these Cmdlets are registered on every node of the cluster. Before
invoking any of these Cmdlets, you must load the snap-in in every PowerShell session. To load the
Snap-In, CLX has provided a PowerShell script file AddClx3PARCmdletsSnapIn.ps1 which
exists at the location <CLX Install Directory>\bin.
You must run this script that will load the PowerShell Snap-In. Once the Snap-In is loaded, you must
run the supported Cmdlets to perform the various required operations. These Cmdlets are available
till the PowerShell session exists. Once the session is closed, the Snap-In will get unloaded and
these Cmdlets will not available.
Another way to unload the CLX PowerShell Snap-In is to run the PowerShell script
RemoveClx3PARCmdletsSnapIn.ps1 located at <CLX Install Directory>\bin directory.
NAME:
Add-CSVDependencyOnCLX3PAR
SYNOPSIS:
Cluster Extension Cmdlets for CSV and Virtual Machine Management 69