HP XP P9500 Storage - Manual (Page 33)

Continuous Access Journal S-VOL is asynchronous, and the secondary system can be located much
greater distances from the local and remote Continuous Access Synchronous sites.
Creating both a Continuous Access Synchronous and a Continuous Access Journal backup insures
that a copy in a third location is available in the event that the primary site or one of the systems
fails.
Configurations consisting of Continuous Access Synchronous and Continuous Access Journal pair
volumes are covered extensively in the HP P9000 Continuous Access Journal User Guide.
Business Copy
Business Copy volumes can be assigned to Continuous Access Synchronous pairs, and Continuous
Access Synchronous volumes can be assigned to Business Copy pairs.
Sharing Continuous Access Synchronous and Business Copy volumes provides multiple copies of
data at the local and/or remote sites.
For information about Business Copy, see the HP P9000 Business Copy User Guide.
NOTE: Business Copy is recommended for in-system copy operations. If Business Copy is not
installed, Continuous Access Synchronous can be used to copy within the same P9500. This
configuration requires at least one fibre cable loop.
Continuous Access Synchronous P-VOLs and S-VOLs can be shared with Business Copy P-VOLs
and S-VOLs.
The Quick Restore operation of Business Copy can be performed on a Business Copy pair when
the Continuous Access Synchronous pair is suspended. For information about the Quick Restore
operation, see the HP P9000 Business Copy User Guide.
Configurations with Business Copy P-VOLs
Continuous Access Synchronous can share a Business Copy P-VOL in three configurations:
1. In the following figure, the Continuous Access Synchronous P-VOL also functions as a Business
Copy P-VOL. This configuration allows you to use Business Copy for onsite data backup in
case of Continuous Access Synchronous failure. Or, the Continuous Access Synchronous S-VOL
can be used to provide remote backup of the Business Copy P-VOL in case of a Business Copy
failure.
Figure 9 Shared Cnt Ac-S P-VOL with BC P-VOL
2. In the following figure, the Continuous Access Synchronous S-VOL also functions as a Business
Copy P-VOL. In this configuration, Business Copy provides another (or several more) backup
copies of a Continuous Access Synchronous P-VOL.
When a Business Copy P-VOL is shared with the Continuous Access Synchronous S-VOL, the
write operation to the Continuous Access Synchronous P-VOL takes a longer time than normally.
This is especially true when the Business Copy pair is in the PSUS(SP) status and is caused by
the Business Copy copying process.
Business Copy 33