HP StorageWorks XP Remote Web Console Software - Manual (Page 20)

20 Overview of Continuous Access XP Journal
Figure 3 shows Continuous Access XP Journal’s connection configuration for multiple secondary arrays.
By connecting one primary array with more than one secondary array, you can create a volume pair that
has a one-to-one relationship for each journal group.
Figure 3 Connection configuration for multiple secondary arrays
Local arrays
Continuous Access XP Journal operations involve local arrays at the primary and secondary sites. The
primary array consists of the main control unit (primary array) and SVP. The secondary array consists of
the remote control unit (secondary array) and SVP.
Operational parameters, or optional modes, are available for the local array to provide greater flexibility
and allow you to tailor the local array to your unique operating requirements. At installation, the local
array modes are set to their default values, so discuss these settings with your HP team. Only your
HP account support representative can change the local array modes.
Main and remote control units (primary and secondary arrays)
The main control unit (primary array) and remote control unit (secondary array) control Continuous Access
XP Journal operations:
• The main control unit controls the primary data volume of the Continuous Access XP Journal pairs and
master journal volume. For Command View XP, the management station must be LAN-attached to the
primary array. The primary array communicates with the secondary array through dedicated remote
copy connections. The primary array controls:
• Host I/O operations to the Continuous Access XP Journal primary data volume
• “Obtain journal” operations for the master journal volume
• Continuous Access XP Journal initial copy operations
• Update copy operations between the primary and secondary data volumes
• The remote control unit controls the secondary data volume of the Continuous Access XP Journal pairs
and restore journal volume. The secondary array controls copying journals and restoring of journals to
the appropriate secondary data volumes. The secondary array assists in managing the Continuous
Access XP Journal pair status and configuration (for example, rejects write I/Os to Continuous Access