HP XP RAID Manager Software - Manual (Page 126)

Figure 46 Concept of paired volumes
Addressing paired logical volumes: The correspondence of paired logical volumes to their physical
volumes is defined by describing the paired logical volume names and group names in the
configuration definition files of each server. It is possible to define a server for the paired logical
volumes in units of group name. Each paired logical volume must belong to a group in order to
determine the corresponding server.
Specification of volumes by commands: Volume names to be used by the Continuous Access
Synchronous commands must be referenced via the paired logical volume names or the group
names.
Using RAID Manager with Business Copy and Continuous Access
Synchronous
RAID Manager allows you to perform Business Copy and Continuous Access Synchronous operations
by issuing Business Copy and Continuous Access Synchronous commands from the UNIX/PC server
host to the RAID storage system. Business Copy and Continuous Access Synchronous operations
are nondisruptive and allow the primary volume of each volume pair to remain online to all hosts
for both read and write operations. Once established, Business Copy and Continuous Access
Synchronous operations continue unattended to provide continuous data backup.
There are specific requirements for using Business Copy and Continuous Access Synchronous in
high-availability (HA) configurations. UNIX/PC servers in HA configurations normally support disk
duplication functions to enhance disk reliability (e.g., mirroring provided by the LVM or device
driver, RAID5 or an equivalent function provided by the LVM). UNIX/PC servers also feature hot
standby and mutual hot standby functions in case of failures on the server side. However, mutual
hot standby for disaster recovery has not yet been achieved since it requires the remote mirroring
function.
Business Copy provides the mirroring function within the storage system. For detailed information
about Business Copy operations, please see the HP P9000 Business Copy User Guide for your
storage system.
Continuous Access Synchronous provides remote mirroring functionality, linkage functionality with
failover switching, and remote backup operations among servers, all of which are required by
UNIX/PC servers in HA configurations for disaster recovery. For detailed information about
126 Data replication operations with RAID Manager