HP StorageWorks XP Remote Web Console Software - Manual (Page 61)

– 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 “Time Stamps of Data that Have Not Been Restored to Secondary
Data Volumes” (page 60) , if a pair in the journal group 1, 2, 3 or 4 is suspended
immediately after data are 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 secondary data volumes. For example, in the case described in
“Time Stamps of
Data that Have Not Been Restored to Secondary Data Volumes” (page 60) , 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
then identify the oldest consistency time. Next, restore all data with time stamps later than the
oldest consistency time, to the secondary data volume. For example, in the case described in
“Time Stamps of Data that Have Not Been Restored to Secondary Data Volumes” (page 60) ,
the consistency time of journal group 2 is the oldest among journal groups 1 to 4. Since the
consistency time of journal group 2 is 14:02, you must restore the following data to secondary
data volumes.
◦ Data with the time stamp 15:00 in journal group 1
◦ Data with the time stamp 15:02 in journal group 2
◦ Data with the time stamp 14:03, and data with the time stamp 15:03 in journal group
3
◦ Data with the time stamp 14:04, and data with the time stamp 15:04 in journal group
4
Connections Among Secondary Storage Systems
If you use more than one primary subsystem and more than one secondary subsystem, you must
establish connections among the secondary subsystems. To do this, you must configure paths and
ports. Also, you must create remote command devices by using HP StorageWorks XP External
Storage Software.
Using More Than One Primary and Secondary Storage System for Remote Console 61