HP XP RAID Manager Software - Manual (Page 16)

Figure 2 Current assignment sequence
Figure 3 Improved assignment sequence
The command device performs the assignment of an instance through TWO phase that has
"temporary allocation (1 0)" and "actual allocation (1 1)" to the instance assignment table.
If the command device will be attacked, the instance assignment table will be filled with "temporary
allocation (1 0)" status, after that the command device will detect a fault of full space as the instance
assignment, and then will clear up all "temporary allocation (1 0)", and re-assigns the required
instance automatically.
This does not require a service personnel to do "OFF/ON" of the command device for clear up
the instance table.
Verifying the RAID Manager instance number
RAID Manager provides a way to verify the number of “temporary allocations (1 0)” and “actual
allocations (1 1)” on the instance table so that you can confirm validity of the RAID Manager
instance number in use. The horcctl -DI command shows the number of RAID Manager
instances since HORCM was started as follows.
Example without command device security:
# horcctl -DICurrent control device = /dev/rdsk/c0t0d0 AI = 14 TI = 0 CI = 1
Example with command device security:
# horcctl -DI
Current control device = /dev/rdsk/c0t0d0 * AI = 14 TI = 0 CI = 1
AI : NUM of Actual instances in use
TI : NUM of temporary instances in RAID
CI : NUM of instances using current (own) instance
Alternate command device function
The RAID Manager software issues commands to the command device via the UNIX/PC raw I/O
interface. If the command device fails in any way, all RAID Manager commands are terminated
abnormally, and you cannot use any commands. Because the use of alternate I/O pathing is
platform dependent, restrictions are placed upon it. For example, on HP-UX systems, only devices
16 RAID Manager software environment