HP XP RAID Manager Software - Manual (Page 133)

Figure 53 Continuous Access Synchronous local system configuration
Continuous Access Synchronous, Business Copy, and Continuous Access
Journal operations
Continuous Access Synchronous/Business Copy volumes
Continuous Access Synchronous commands allow you to create volume pairs consisting of one
primary volume (P-VOL) and one secondary volume (S-VOL). The Continuous Access Synchronous
P-VOL and S-VOL can be in different storage systems. Continuous Access Synchronous provides
synchronous and asynchronous copy modes. Continuous Access Asynchronous can only be used
between separate storage systems (not within one storage system). For details on Continuous Access
Synchronous specifications, volumes and operations, please see the HP P9000 Continuous Access
Synchronous User Guide for your storage system.
Business Copy commands allow you to create volume pairs consisting of one P-VOL and up to nine
S-VOLs using the Business Copy cascade function. Business Copy pairs are contained within the
same storage system and are maintained using asynchronous update copy operations. For details
on Business Copy specifications volumes and operations, please see the HP P9000 Business Copy
User Guide for your storage system.
Each volume pair that you want to create must be registered in the RAID Manager configuration
file. Business Copy volume pairs must include a MU (mirrored unit) number assigned to the S-VOL.
The MU number indicates that the pair is a Business Copy pair and not a Continuous Access
Synchronous pair. Once the correspondence between the paired logical volumes has been defined
in the HORCM_DEV section of the configuration file, you can use the configuration file to group
the paired volumes into volume groups that can be managed by the host operating system’s LVM
(logical volume manager).
The host’s LVM allows you to manage the Continuous Access Synchronous/Business Copy volumes
as individual volumes or by volume group. Continuous Access Synchronous/Business Copy
commands can specify individual logical volumes or group names. For LUSE volumes, you must
enter commands for each volume (LDEV) within the expanded LU. If you define volume groups and
you want to issue commands to those volume groups, you must register the volume groups in the
configuration file. For further information about the server LVM, see the user documentation for
your corresponding operating system.
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