HP XP P9500 Storage - Manual (Page 147)

Figure 52 Continuous Access Asynchronous consistency groups
Restrictions
•
Group definition of Continuous Access Asynchronous/Continuous Access Journal/Continuous
Access Synchronous volume: All volumes in a group must be contained within the same storage
system. If two or more groups of RAID Manager include the same CT group (CTGID), then
pair operation of the group specification is handled in CT group entirety.
•
Registration of CTGID number and limitations: RAID Manager registers CTGID to RAID disk
array automatically when paired volumes are created by paircreate command, and groups
of configuration definition files are mapped to CTGID. The maximum number of CT groups is
256 for P9500 and XP24000/XP20000 Disk Array (CTGID0 to CTGID255), 128 for XP12000
Disk Array/XP10000 Disk Array (CTGID0 to CTGID127), 64 for XP1024/XP128 Disk Array
(CTGID0-CTGID63), and 16 for XP512/XP48 Disk Array (CTGID0 to CTGID15). Continuous
Access Asynchronous/Continuous Access Journal pair command is terminated with
EX_ENOCTG when the maximum number of CT groups is exceeded.
•
Relationships between CTGID and Journal ID: CT group numbers 0-127 are used for Continuous
Access Asynchronous, Continuous Access Synchronous, and Continuous Access Journal. The
rest of the CT group numbers 128-255 are used only for Continuous Access Journal, and are
mapped to the journal.
Table 33 Assignment of consistency group IDs (CTGIDs)
Assignment CTGID
CTG 0-127 Continuous Access Asynchronous 0 -127
Continuous Access Synchronous
CTG 0-127 Continuous Access Journal
CTG 128-255 Continuous Access Journal 128 - 255
Continuous Access Synchronous, Business Copy, and Continuous Access Journal operations 147