HP MPIO Full Featured DSM for P9000 family of Disk Arrays 4.02.00 installation and reference guide (AA-RVJ6M-TE, October 2010)

3 Support for load balancing in Microsoft
Cluster Server environments for Windows
Server 2003
This section describes the following:
• Enabling or disabling support for load balancing in MSCS environments
• Recovering inaccessible disk devices
By default, in HP MPIO P9000 DSM, load balancing is enabled in Microsoft Cluster Server (MSCS)
environments. The MSCS uses SCSI-2 reservations to synchronize access to the cluster-managed
devices. However, HP MPIO P9000 DSM provides a feature to support load balancing for all HP
disk arrays that support the SCSI-3 persistent reservations management method by mapping the
MSCS-issued SCSI-2 reservations to SCSI-3 persistent reservations.
HP MPIO P9000 DSM supports load balancing in MSCS environments only under the following
conditions:
• All nodes in the cluster must have the same version of the HP MPIO P9000 DSM installed.
• Support for load balancing in MSCS environments must be enabled on all cluster nodes in the HP
MPIO P9000 DSM.
• The disk array containing the cluster resources must support the SCSI-3 persistent reservations.
You can enable or disable the load balancing support in MSCS environment anytime after the HP
MPIO P9000 DSM installation.
NOTE:
• Contact HP technical support for details on disk arrays and the firmware revisions that support
persistent reservations.
CAUTION:
You must have the same setting for the load-balancing feature on all the nodes in a cluster. If the
setting is not consistent across all cluster nodes, the cluster node failover functionality can be impaired.
Enabling or disabling support for load balancing in MSCS
environments
You can enable or disable the load balancing support in MSCS environment in HP MPIO P9000
DSM by performing the following steps:
HP MPIO Full Featured DSM for P9000 family of Disk Arrays 4.02.00 installation and reference
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