HP StorageWorks XP Remote Web Console Software - Manual (Page 91)

R-VOL/
Primary data
volume
Master
JNLVOL
Restore
JNLVOL
Primary site
Intermediate
site
Secondary
site
M-VOL
Secondary
data volume
I/O I/O finished
Transfer
asynchronously
Transfer
synchronously
Finished storing
data
Figure 36 Basic Behavior in 3DC Cascading Configuration
If a TCz Synchronous pair is suspended in a 3DC cascading configuration, you will be able to
resynchronize the pair by using differential copy. If a URz pair is suspended, you will be able to
resynchronize the pair by using differential copy.
NOTE:
To perform disaster recovery from a failure in the primary site in a 3DC cascading configuration, you
must ensure that the fence level of the TCz Synchronous M-VOL is Data (CRIT=Y (ALL))). If this fence level
is specified, you can perform disaster recovery by using the URz secondary data volume that contains
the data stored in the TCz Synchronous M-VOL.
Hardware Configuration
This section explains hardware configuration for a 3DC cascading configuration using TCz Synchronous
and UR-z/OS. In a 3DC cascading configuration, three XP storage systems are required. It is
recommended that Business Continuity Manager is installed on hosts in the primary site, the intermediate
site, and the secondary site. XP Remote Web Console computers are required for these sites. The
following explains hardware configuration for these sites.
• Primary site
• The XP storage system must have TCz Synchronous installed.
• The XP storage system must have TCz Synchronous M-VOL.
• Storage system settings must be made so that Business Continuity Manager can be used. For
detailed information about settings required for using volumes in a remote site, please refer to
Business Continuity Manager User’s Guide.
• Intermediate site
• The XP storage system must have TCz Synchronous installed.
• The XP storage system must have URz installed.
• The XP storage system must have a volume used as both a TCz Synchronous R-VOL and a
URz primary data volume.
• The XP storage system must have a URz master journal volume.
• Storage system settings must be made so that Business Continuity Manager can be used. For
detailed information about settings required for using volumes in a remote site, please refer to
Business Continuity Manager User’s Guide.
• Remote site
• The XP storage system must have URz installed.
• The XP storage system must have a URz secondary data volume.
• The XP storage system must have a URz restore journal volume.
• Storage system settings must be made so that Business Continuity Manager can be used. For
detailed information about settings required for using volumes in a remote site, please refer to
Business Continuity Manager User’s Guide.
Hitachi Universal Replicator for z/OS user guide for XP12000/XP10000 Disk Arrays and SVS 200 91