HP StorageWorks XP Remote Web Console Software User Manual
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Table 3 Specifications of Extended Consistency Groups
Specifications
Item
Up to four per one-storage system
The number of extended consistency groups that can be created
Up to 16
The number of journal groups that can be registered in one extended
consistency group
The configuration of both the primary and secondary extended consistency groups (EXCTGs)
provides the following benefits:
•
Guaranteed Consistency of Data Update Sequence
Universal Replicator for Mainframe restores journal data to secondary data volumes by taking
the following steps. This procedure guarantees the consistency of the data update sequence
within an extended consistency group.
1.
Universal Replicator for Mainframe checks the extended consistency group for the time
stamps of all journal data that have not been restored to secondary data volumes, and
then identifies the latest time stamp for each journal group.
In the example shown in
, the latest time stamp for each journal group
is as follows:
◦
In journal group 1, the latest time stamp is 15:00.
◦
In journal group 2, the latest time stamp is 15:02.
◦
In journal group 3, the latest time stamp is 15:03.
◦
In journal group 4, the latest time stamp is 15:04.
2.
Universal Replicator for Mainframe searches for the oldest time stamp from the ones
identified in step
and restores data up to that time to the secondary volumes.
In the example shown in
, the oldest time stamp is 15:00. Universal
Replicator for Mainframe restores all data that have a time stamp 15:00 or earlier to the
secondary data volumes.
◦
For journal group 1, Universal Replicator for Mainframe restores all data up to 15:00.
◦
For journal group 2, Universal Replicator for Mainframe restores all data up to 14:02.
◦
For journal group 3, Universal Replicator for Mainframe restores all data up to 14:03.
◦
For journal group 4, Universal Replicator for Mainframe restores all data up to 14:04
Components
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