HP StorageWorks XP Remote Web Console Software - Manual (Page 99)

Chapter 3 Preparing for Universal Replicator z/OS Operations 3-33
Hitachi Universal Replicator for IBM /OS User’s Guide
The procedure to use the At-Time Split function when you combine URz with
ShadowImage for z/OS
® is as follows. The following steps enable you to make
backup copy at a specified time without suspending URz pairs.
1. Specify the split time by using Business Continuity Manager.
2. Among the URz restore journals, the journal data created before the split
time is restored to URz S-VOLs (SIz S-VOLs).
3. When URz detects the journal data from the restore journal which has the
time stamp later than the split time, restore operations will be suspended.
After that, split operations will be executed on SIz pairs which are in
conjunction with URz S-VOL.
4. After SIz has completed the split operations, URz will resume the
suspended restore operation of the restore journal.
Caution: If you use the At-Time Split function when combining URz with SIz,
mind the following:
– Make sure that all of the URz S-VOLs are paired with SIz volumes. Also,
all of the SIz pairs in conjunction with URz S-VOLs must belong to the
same ShadowImage for z/OS ® consistency group. If all the URz S-VOLs
are not paired with SIz volumes, or if SIz pairs in conjunction with URz
S-VOL belong to different ShadowImage for z/OS
® consistency groups,
consistent backup copy operations cannot be executed.
– When you execute split operation, the URz pair status must be duplex,
and the SIz pair status must be either duplex or pending. If the status
of the URz pair or the SIz pair is suspended due to a failure, the journal
data which was created before the split time may not be restored to the
SIz T-VOL after the split operation has been completed.
– The split time and the actual starting time of the split operation are not
necessarily the same. The starting time of the split operation will delay
depending on the amount of journal data stored in the journal volume
at the split time. For example, if journal data that needs one hour to be
completely restored is stored at the split time, the starting time of the
split operation will delay for one hour.
– Even if the specified timeout period has passed from the split time,
journal data with the time stamp later than the split time may not be
detected due to some reason such as a lot of journal data stored in the
journal volume. If the journal data with such a time stamp cannot
detected, the split operation of SIz pair will be executed after the
specified timeout period. Since the time out value is variable, please set
the value according to your environment. The default time out value is
6 hours. For a guide to set the time out value, please refer to the
Guideline for the Timeout Menu Setting When Using At-Time Split
Function at Combining Universal Replicator with ShadowImage. For
details on how to specify a timeout value, please refer to the Business
Continuity Manager™ User's Guide.
Note: If you use the At-Time Split function when combining URz with
SIz, note the following: