HP XP Continuous Access Software - Manual (Page 22)

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 is responsible for 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 connection paths. The primary array controls:
• Host I/O operations to the Continuous Access XP Journal primary data volume
• “Obtain journal” initial 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 the 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
22 Overview of Continuous Access XP Journal