HP StorageWorks XP Remote Web Console Software - Manual (Page 122)

122 TrueCopy for the XP128/XP1024/XP10000/XP12000
(R-VOL or M-VOL failure) and fence level pair option determine whether the M-VOL will accept write
I/O operations after the pair is split.
CAUTION: If you need to split a pair and the M-VOL is required for system operation, do not use
the M-VOL Failure suspend kind option. Make sure to use the R-VOL suspend kind option so that the
M-VOL continues accepting I/Os.
6. If you want to execute the Suspend Pair requests quickly, select the Use Time-Saving Mode check box
above the Pair Settings Parameter list (Suspend Pair).
7. Click Apply on the TrueCopy main window to split the specified pair(s). For the TC390 Synchronous
pairs, the MCU will complete all M-VOL write operations in progress and the associated update copy
operations at the R-VOL before splitting the pair so that the pair is synchronized at the time of Suspend
Pair.
8. From the TrueCopy main window, verify that the TC390 pair(s) is/are displayed correctly (Suspended
status) in the Volume list. The Resume Pair command (see ” Resuming TrueCopy Volume Pairs (Resume
Pair) ” on page 123) resumes suspended TC390 volume pair(s).
CAUTION: If a timeout error occurs after clicking the Use Time-Saving Mode option, confirm on the
TrueCopy main window for which volumes the Suspend Pair operation could not be performed.
Deselect the Use Time-Saving Mode option for the failed volume and retry the Suspend Pair
operation.
Resuming TrueCopy Volume Pairs (Resume Pair)
While a TC390 pair is suspended, the MCU does not perform any update copy operations. For a
suspended TC390 Synchronous pair, the MCU may or may not continue accepting write I/Os for the
M-VOL depending on the M-VOL fence level and suspend option (if user-requested). If the MCU accepts
write I/Os for a suspended M-VOL, the MCU keeps track of the M-VOL cylinders that are updated while
the pair is suspended, and then copies the VOLSER and out-of-sync cylinders to the R-VOL when the pair is
resumed. For a suspended TC390A pair, the MCU and RCU keep track of any recordsets that were
discarded during suspension, and the MCU continues accepting write I/Os for the M-VOL. When a
TC390A pair is resumed, the MCU merges the M-VOL and R-VOL cylinder bitmaps and then copies the
VOLSER and out-of-sync cylinders to the R-VOL to resynchronize the pair.