HP P6000 Cluster Extension Software Administrator Guide (5697-2274, November 2012)

MSCS
MSCS depends on a quorum resource to maintain a persistent log of cluster configuration changes
and status, as well as a single point to resolve any possible events that could result in a split-brain
situation. P6000 Cluster Extension supports the following quorum configurations in which one site
failure will not cause the entire cluster to fail.
Windows Server 2008/2008 R2/2012
• Node Majority
• Node and File Share Majority
Storage system configurations
Cluster configurations typically consist of two or more server systems connected to a shared storage
system. P6000 Cluster Extension allows the dispersion of data center resources by enabling cluster
systems to take advantage of P6000/EVA storage systems configured for P6000 Continuous Access
operations. P6000 Cluster Extension connects the P6000 management software used to control
P6000/EVA storage systems (and P6000 Continuous Access) with the cluster software and uses
the cluster software to react to system hardware and application failures.
P6000 Cluster Extension behavior is based on four major considerations:
• Cluster software failover behaviors
• P6000 Cluster Extension user settings
• The replication mode setting for P6000 Continuous Access, which is used to configure the
remote replication feature of a P6000/EVA storage system environment based on your needs
for application service availability, data concurrency, and replication performance
• DR group member status information
P6000 Cluster Extension supports one-to-one and consolidated DR site configurations.
One-to-one configuration
When setting up a one-to-one configuration (see Figure 2 (page 9)), consider the following:
• Cluster host nodes are split between two or more geographically dispersed data center sites
and use redundant, diversely routed network connections for intra-cluster communications.
Those links must be as reliable as possible to prevent false failover operations or split-brain
situations.
• Each cluster host node connected to a P6000/EVA storage system should have redundant
I/O paths to the P6000/EVA storage system. Connections to both the source (primary) and
the destination (secondary) copy of the application disk set are not allowed from the same
host. Configure your servers only in the zone that allows access to the local P6000/EVA
storage system.
• HP recommends a minimum of two cluster host nodes per site. This allows for preferred local
failover in case of system failure. Local failover operations are faster than remote failover
between P6000/EVA storage systems because you do not need to change the mirroring
direction of the DR group members.
• You can deploy P6000 Cluster Extension in environments where several clusters use the same
P6000/EVA storage system pair.
• You can use P6000 Continuous Access in synchronous replication mode with P6000 Continuous
Access between two P6000/EVA storage systems connected using FC switches and extender
hardware.
• You can use P6000 Continuous Access in enhanced asynchronous mode with P6000 Cluster
Extension 4.00.01 and later for Windows.
8 P6000 Cluster Extension features