HP XP Racks - Manual (Page 101)

Figure 54 BC Z Backup configuration example using the NORMAL ATTIME Suspend function
Before backup using the NORMAL ATTIME Suspend function, the normal status of each Business
Copy Z copy group is SUSPOP.
When using the NORMAL ATTIME Suspend function to perform a backup operation for Business
Copy Z :
1. Execute the YKRESYNC command for the Business Copy Z copy group.
2. Execute the YKSUSPND command to execute the NORMAL ATTIME Suspend function for the
Business Copy Z copy group.
A backup of the Business Copy Z P-VOL at 2007/1/1 10:00 can be acquired in the Business
Copy Z S-VOL.
When suspensions are executed (NORMAL ATTIME Suspend function)
Once the NORMAL ATTIME Suspend function is executed, circumstances dictate when copy group
suspension takes place. The consistency of the copy group is preserved even if a copy group
suspension occurs at either of the following times.
•
When an I/O operation is detected after the specified ATTIME suspend time:
If the storage system detects an I/O to a P-VOL that has a timestamp after the specified
NORMAL ATTIME suspend time, suspension is executed. The detected I/O is not reflected
into the S-VOL.
•
When a timeout occurs:
If the storage system detects no I/O activity after the specified ATTIME suspend time has
elapsed, suspension is executed.
NORMAL ATTIME Suspend function: recommendations for backing up multiple generations
When the NORMAL ATTIME Suspend function is used for the Business Copy Z copy group, if the
copy group is resynchronized and is changed to the DUPLEX status, the S-VOL cannot be used as
a volume for recovery until the next time the copy group is suspended. Therefore, we recommend
that you prepare copy groups for two or three generations and have one copy group of the above
generations always in the suspend status for recovery.
When backing up multiple generations, you can manage those generations by using generation
IDs. If you set a different generation ID each time you back up a copy group, recognizing copy
groups that were backed up across multiple storage systems at the same time will be easier.
The Specified Time Suspend function 101