HP XP Continuous Access Software - Manual (Page 68)

Notes on performing Delta Resync Operations
Before performing delta resync operations, specify an XP Continuous Access Journal pair belonging
to the journal group whose XP Continuous Access Journal pairs meets the following requirements:
NOTE: In the journal group, even if the specified pair satisfies requirements, an error may occur
when any XP Continuous Access Journal pair does not satisfy the requirements.
•
Status of the primary data volume is HOLD.
•
The XP Continuous Access Journal pair for delta resync operation uses a volume of one mirror
in the journal group as the primary data volume.
◦ If you use the primary volume of one mirror in the journal group, the pair status should
be PAIR.
◦ If you use the secondary volume of one mirror in the journal group, the pair status should
be SSWS.
•
The secondary data volume uses two mirror IDs; the status of the secondary volume that uses
one of the two mirror IDs is HOLD, and the status of the secondary volume that uses another
mirror ID is PAIR, PSUS, or PSUE.
•
All differential data between the primary and secondary data volume is stored in the primary
journal group.
After creating the XP Continuous Access Journal pair for delta resync operation (or if the failure
occurred at the primary site right after the recovery of XP Continuous Access Journal pair),
only a part of the differential data between the primary and secondary data volume may be
stored in the primary journal group.
•
The path between the primary and secondary sites to which the XP Continuous Access Journal
pair for delta resync operation belongs is available.
If the delta resync operation to support remote command devices is performed, you can execute
the delta resync operation directly after the primary site is updated.
Consider the following when creating the XP Continuous Access Journal pair for delta resync
operation:
◦ When the XP Continuous Access Journal pair status changes to HOLD after the delta
resync operation.
◦ When you re-create the XP Continuous Access Journal pair for delta resync operation
when recovering the primary site.
If the delta resync operation to support remote command devices is performed, you can execute
the delta resync operation directly after the primary site is updated.
•
The secondary volume of the XP Continuous Access Journal pair for delta reysnc operation is
not a virtual volume of XP Thin Provisioning.
•
The secondary volume of the XP Continuous Access Journal pair for delta resync operation is
not assigned to the primary volume of XP Business Copy.
If any XP Continuous Access Journal pair in the journal group does not meet the above requirements,
an error occurs or the operation is suspended by failure and delta resync operation will fail, even
if the specified XP Continuous Access Journal pair meets the requirements. In the following cases,
68 Preparing for XP Continuous Access Journal Operations