HP EVA Cluster Extension Software Administrator Guide (5697-2445, July 2013)

User configuration file
EVA Cluster Extension provides a user configuration file to customize failover behavior. You can
specify all customizable objects of the EVA Cluster Extension in this file.
For more information, see User configuration file (page 48).
Force flag
The force flag forces EVA Cluster Extension to skip the internal logic and enables write access to
the local vdisks regardless of the DR group member state. You can set this flag when you are sure
that the current site contains the latest data, even though a previous application service startup
process failed because EVA Cluster Extension discovered a DR group member state that could not
be handled automatically.
To use the force flag feature, before starting the application service that uses EVA Cluster Extension,
you must create a file called application_name.forceflag in the directory specified by the
ApplicationDir property. The application_name is the name of the Cluster Extension EVA
resource. Before creating this file, ensure that the application service is not running elsewhere. This
file is removed after it is detected by the EVA Cluster Extension.
You cannot use the force flag if the local vdisk state is a combination of destination and copying,
which indicates that a copy operation is in progress. A disk cannot be put in read/write access
mode when a write operation to that vdisk is in progress; in this case, EVA Cluster Extension returns
a global error.
Planning for EVA Cluster Extension
Consider the dependencies described in this section before configuring EVA Cluster Extension.
HP P6000 Command View and HP EVA SMI-S dependencies
EVA Cluster Extension depends on HP P6000 Command View and HP EVA SMI-S, as well as the
cluster software it is integrated with.
Before you configure EVA Cluster Extension, verify that the host and storage systems are properly
configured. Ensure that:
• The storage system and its remote peer have been properly configured.
• The host system recognizes the storage systems.
• The EVA Continuous Access links are working properly in both directions.
• You are familiar with the disk configuration of the operating system.
HP SMI-S configuration
When using HP EVA SMI-S and EVA Cluster Extension, note the following requirements:
• To function properly, EVA Cluster Extension requires at least one instance of HP EVA SMI-S
running on a management server. You must, therefore, set up at least one management server
with HP SMI-S in each data center.
• In an EVA Continuous Access environment, both EVA storage systems should be actively
managed by the same management server during the EVA Cluster Extension resource
configuration procedures. After resources are configured, EVA Cluster Extension can complete
failover with a management server that is passively or actively managing the array.
• If EVA Cluster Extension cannot connect to the first management server in the list, it can switch
to any of the configured HP EVA SMI-S instances on the alternate management servers. To
interface with the local array, EVA Cluster Extension tries all local management servers before
resorting to the remote management servers. To interface with the remote array, EVA Cluster
Extension will also try the local management servers first, unless the intersite links are down.
User configuration file 13