HP StorageWorks Continuous Access XP Journal user guide (December 2005)

Continuous Access XP Journal user guide 39
Journal groups
Continuous Access XP Journal journal groups have the following requirements:
• Each Continuous Access XP Journal pair must be assigned to one and only one journal group.
• Table 14 lists journal group specifications.
The same number of journal volumes is not required in the master journal group and the restore journal
group that are paired.
A mirror ID is required for a configuration that will be supported in the future as 3-data center (3DC)
configuration. In the future, HP might support setting two or more restore journal group for one master
journal group. Each pair relationship in a journal group is called “Mirror.” The Mirror ID identifies two
or more mirrors for one journal group. The same Mirror ID is applied for the data volume pair. See
”Combining Continuous Access XP Journal with Continuous Access XP (3DC cascading configuration)”
on page 60 for more information.
• Table 15 describes the relationship between data volumes, between journal volumes, and between the
data volume and journal volume in a journal group.
Table 14 Journal group specifications
Item Support specifications
Number of journal groups Up to 256 journal groups (No. 0 - 255) per disk array if all the
following conditions are satisfied:
• Disk array is an XP12000 (not an XP10000).
• Microprogram version is 50-05-00-00 or later.
• Shared memory options #3, #4, and #5 are already
installed.
• High Performance mode is applied to shared memories.
NOTE: Only the HP service engineer can install shared memory
options and apply High Performance mode. If necessary, contact
your HP account support representative.
Up to 16 journal groups (No. 0 - 15) per disk array if any of
these conditions are not satisfied.
Number of data volumes in journal group Up to 4,096
Number of journal volumes in journal group Up to 16
Number of Mirror IDs Up to 4 (ID No.: 0 to 3)
NOTE: If Continuous Access XP (synchronous) uses No. 0, No. 1
to 3 are available for Continuous Access XP Journal.
Table 15 Volume specifications in journal group
Item Support specification
Emulation type Same or different emulation types are available
NOTE: Only Open-V can be used for journal volumes.
Volume capacity Same or different capacity is available