HP P6000 Continuous Access Implementation Guide (T3680-96431, August 2012)

DR group Data Replication group. A logical group of virtual disks in a remote replication relationship with
a corresponding group on another array.
DR group member
states
Normal. Remote replication involving the virtual disk is normal. There is no logging or merging
involving the virtual disk.
Full Copy. The DR group log threshold has been reached and the virtual disk is involved in a full
copy.
Async Merging (Adding). The virtual disk is a member of an enhanced asynchronous DR group,
and is performing a full copy. This can happen when a virtual disk is added to a DR group or
the DR group log is full.
Async Merging (Removing). The virtual disk is a member of an enhanced asynchronous DR group,
and is being removed from a source DR group. Removal completes when all transactions in the
DR group log have merged to the destination DR group virtual disk.
Async Merging (Shrinking). The virtual disk capacity is being reduced. This can occur for
synchronous, basic asynchronous, or enhanced asynchronous DR groups.
Unknown. The virtual disk copy state cannot be determined.
DR relationship When one EVA mirrors data to a second, remote EVA, they are said to have a DR relationship.
dual fabrics Two independent fabrics providing multipath connections between Fibre Channel end devices.
E
enabled host A host that is equipped with a replication manager host agent.
enhanced
asynchronous
A write mode in which all host write I/Os are added to write history log. The controller then
acknowledges that data has been written at the source before the data is copied at the destination.
event Any significant change in the state of the Enterprise storage system hardware or software
component reported by the controller to HP P6000 Command View.
F
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. Failovers can be planned or unplanned and can occur
between DR groups, managed sets, fabrics or paths, and array controllers.
failsafe A safe state that devices automatically enter after a malfunction. Failsafe DR groups stop accepting
host input and stop logging write history if a group member becomes unavailable.
fast copy The process for quickly synchronizing the data on a source virtual disk and a destination virtual
disk by coping only data blocks that have changed. As I/O is written to the write history log, a
bitmap tracks the region of the virtual disk written. Only the regions that are indicated by the
corresponding bit in the bitmap are copied to the destination virtual disk. This process synchronizes
the source and destination virtual disks faster than a full copy.
full copy The process of copying all data written on a source virtual disk directly to the destination virtual
disk. If a data block contains all zeros, a zeroing message is sent to the destination array's virtual
disk for the corresponding data block. This minimizes the amount of data that must be written to
the destination virtual disk. When the full copy is complete, the source and destination virtual
disks contain the same data (synchronized).
G
GBIC Gigabit Interface Converter
GBps Gigabytes per second. A measurement of the rate at which the transfer of bytes of data occurs.
A GBps is a transfer rate of 1,000,000,000 (109) bytes per second.
Gbps Gigabits per second. A measurement of the rate at which the transfer of bits of data occurs.
Nominally, a Gb is a transfer rate of 1,000,000,000 (109) bits per second.
132 Glossary