HP StorageWorks XP Remote Web Console Software User Manual
Page 24
Figure 4 Time Stamps of Data that Have Not Been Restored to Secondary Data Volumes
•
Consistency Time
In the Universal Replicator for Mainframe windows, consistency times of extended consistency
groups, journal groups, and data volume pairs are displayed. These consistency times have
the following meanings:
◦
The consistency time of an extended consistency group is the latest time stamp of the
restored data in the group in which consistency is guaranteed.
In the example shown in
, the consistency time of the extended
consistency group is 15:00.
◦
The consistency time of a journal group is the latest time stamp of the restored data.
In the example shown in
, the consistency times of journal groups 1
to 4 are as follows:
–
The consistency time of journal group 1 is 15:00.
–
The consistency time of journal group 2 is 14:02.
–
The consistency time of journal group 3 is 14:03.
–
The consistency time of journal group 4 is 14:04.
◦
The consistency time of a data volume pair is the latest time stamp of the data that has
been restored when the pair becomes suspended.
In the example shown in
, if a pair in journal group 1, 2, 3, or 4 is
suspended immediately after data has been restored, the consistency time of the pair will
be as follows:
–
If a pair in journal group 1 is suspended, the consistency time will be 15:00.
–
If a pair in journal group 2 is suspended, the consistency time will be 14:02.
–
If a pair in journal group 3 is suspended, the consistency time will be 14:03.
–
If a pair in journal group 4 is suspended, the consistency time will be 14:04
If a failure occurs in a primary storage system and then you want to recover from the failure,
restore journal data with time stamps later than the consistency time of the extended consistency
group to the secondary data volumes. For example, in the case described in
, the consistency time of the extended consistency group is 15:00, and therefore you must
restore the following data to secondary data volumes:
◦
Data with the time stamp 15:02 in journal group 2
◦
Data with the time stamp 15:03 in journal group 3
◦
Data with the time stamp 15:04 in journal group 4
If a failure occurs in a secondary storage system and then you want to recover from the failure,
compare the consistency times of all journal groups in the extended consistency group, and
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About Universal Replicator for Mainframe Operations