HP P6000 Cluster Extension Software Administrator Guide (5697-0986, June 2011)

DR group log state The current behavior of the log associated with a DR group. In the state options,
references to multiple destinations are for future use. There are three possible
states:
• Normal – No destination is logging or merging.
• Logging – At least one destination is logging; none are merging.
• Merging – At least one destination is merging.
DR group write
mode
Characterizes how a write from a host is replicated. A DR group has two modes
of replication writes from the source vdisk to the destination vdisk:
• Synchronous replication—I/O requests to both source and destination must
be complete before the storage system processes the next I/O request from
the host.
• Asynchronous replication—The storage system processes the next I/O request
on the source even if there are outstanding I/O requests on the destination.
This mode is not available at this time.
DR mode The operational mode of a DR group that indicates the capability of I/O to be
written to its source and/or its destination.
DSM Device Specific Module.
dual fabric Two independent fabrics providing multipath connections between Fibre Channel
end devices.
DWDM Dense wavelength division multiplexing. The technique of placing many optical
signals on a single optical cable simultaneously.
See also WDM
enhanced
asynchronous
mode
A write mode in which all host write I/Os are added to the write history log. The
controller then acknowledges that data has been written at the source before
being copied at the destination.
Enterprise Virtual
Array (EVA)
An HP storage product that consists of one or more virtual arrays. See also virtual
arrays.
fabric A network of Fibre Channel switches or hubs and other devices.
failover An operation that reverses replication direction so that the destination becomes
the source and the source becomes the destination. Failover operations can be
planned or unplanned and can occur between DR groups, managed sets, fabrics
or paths, and array controllers.
failsafe mode A DR group mode in which all source vdisks in the group become both unreadable
and unwritable if any of their corresponding destination vdisks is unreachable.
No logging takes place for the vdisks. There are two states:
• Enabled
• Disabled
FC Fibre Channel. A network technology primarily used for storage networks.
FC connection A FC path between two storage systems or between a host and its storage. A
connection is made up of multiple FC links.
fencing The mechanism that prevents data corruption by removing an errant node from
a cluster.
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