HP StorageWorks XP Remote Web Console Software - Manual (Page 10)

XP Continuous Access supports the following RAID level configurations.
Table 2 XP Continuous Access supported RAID level configurations
For S-VOL For P-VOL
RAID 1 RAID 1
RAID 6 RAID 1
RAID 5 RAID 5
RAID 5 RAID 1
RAID 1 RAID 5
RAID 6 RAID 5
RAID 1 RAID 6
RAID 5 RAID 6
RAID 6 RAID 6
XP Continuous Access Synchronous consistency groups
An XP Continuous Access Synchronous consistency group is a user-defined set of volume pairs. If
you specify consistency group for XP Continuous Access Synchronous pairs, you can issue a
command for each group and you can also ensure the consistency of these pairs in the same group.
If the split command (Pairsplit-r) is issued to the corresponding consistency group, and if the I/O
processing on some volumes in the consistency group has not finished, the split operation to the
volume pair is executed after the I/O processing and the data transfer to S-VOL have finished.
Even if the suspend operation caused by system failure has occurred to the pairs in a consistency
group, the suspend operation to the volume is executed similarly. The suspend operation to the
volume is executed after the I/O processing and the data transfer to S-VOL have finished with
ensuring the data consistency of the pairs in the corresponding group.
You can ensure consistency of data of volumes in the same DKC. XP Continuous Access allows
you to configure up to 128 consistency groups (00-7F) for each MCU.
For detailed information about synchronous consistency groups, see “XP Continuous Access
Synchronous consistency group operations” (page 20) .
Synchronous consistency groups can be defined and operated only by XP RAID Manager. For
details, see the HP StorageWorks XP RAID Manager User's Guide.
XP Continuous Access Asynchronous consistency groups
An XP Continuous Access Asynchronous consistency group is a user-defined set of volume pairs
across which update sequence consistency is maintained and ensured at the remote site. Each XP
Continuous Access Async volume pair must be assigned to a consistency group. XP Continuous
Access can configure up to 128 consistency groups (0-7F) for each MCU and provides group-based
operations for consistency groups (for example, split and resync group). Use consistency groups
to maintain update sequence consistency for databases spanning multiple volumes, allowing
immediate database recovery at the remote site when needed. See
“XP Continuous Access
Asynchronous consistency group operations” (page 22) for further information.
Only XP Continuous Access Asynchronous pairs belonging to the same CLPR can be allocated to
one XP Continuous Access consistency group. For more information about CLPRs, see the
HP StorageWorks XP Disk/Cache Partition user guide for XP12000/XP10000 Disk Arrays and
SVS200.
10 Overview of XP Continuous Access operations