Recovering from failures in the primary site – HP StorageWorks XP Remote Web Console Software User Manual
Page 97
When either of the abovementioned requirements is not fulfilled, usually an error occurs and delta
resync operation will fail. Especially in the following cases, delta resync operation will not be performed
since the necessary journal data does not exist:
•
When the primary data volume in the URz pair for delta resync operation is updated after
creating the URz pair, but URz primary data volumes that are also used as TCz Synchronous
primary data volumes are not updated in the primary site
•
When the volumes in the primary site are updated after splitting TCz Synchronous pair
•
When the secondary data volume is updated after splitting URz pair
•
As a result of the update of the primary data volume after splitting URz pair, when the capacity of
the journal data exceeds 70% of the journal volume in TCz Synchronous secondary site
•
When the primary data volume in the URz pair for delta resync operation is updated and then
the capacity of the journal data exceeds 70% the journal volume in the primary site of URz pair
for delta resync operation
•
When no volumes (including volumes after failover or failback) in the primary site are updated
after creating the URz pair for delta resync operation
•
When delta resync operation is performed within about one minute after a volume in the primary
site is updated after the URz pair for delta resync operation is created
Note:
By specifying an option, you can copy the whole data in the primary volume to the secondary
volume and avoid the error when only a part of the differential data between primary and secondary
data volume is stored in the journal volume. For detailed information about the option, see
Changing Options for a Journal Group
Recovering from Failures in the Primary Site
If you follow the operation procedure in
Recovering from Failures in the Primary Site and the TCz Synchronous Secondary Site
and then the system does not change to 3DC cascading configuration, you can change the system into
3DC multi-target configuration after removing failures from the primary site and other locations, The
resulting 3DC multi-target system uses the former TCz secondary volume as a primary volume.
To change the system into 3DC multi-target configuration:
1.
Use Business Continuity Manager to execute the YKDELETE command on the journal group
corresponding to the former URz pair.
NOTE:
YKDELETE is a command for releasing a pair.
2.
If pair resynchronization has not been performed to reverse the primary volume and the remote
volume of the TCz Synchronous pair (i.e., if the pair is suspended), use Business Continuity
Manager to execute the YKRESYNC command, so that the copy direction of the TCz Synchronous
pair will be reversed.
NOTE:
YKRESYNC is a command for re-establishing a pair.
Hitachi Universal Replicator for z/OS user guide for XP12000/XP10000 Disk Arrays and SVS 200
97