HP XP P9500 Storage - Manual (Page 21)

Figure 9 HORCM operational environment
RAID Manager instance configurations
The basic unit of the RAID Manager software structure is the RAID Manager instance. Each copy
of RAID Manager on a server is a RAID Manager instance. Each instance uses its own configuration
definition file to manage volume relationships while maintaining awareness of the other RAID
Manager instances. Each RAID Manager instance normally resides on separate servers (one node
per instance). If two or more instances are run on a single server (e.g., for test operations), it is
possible to activate two or more instances using instance numbers. The RAID Manager commands
to be used are selected by the environment variable (HORCC_MRCF). The default command
execution environment for RAID Manager is Continuous Access Synchronous.
The RAID Manager instance shown in the following figure has a remote execution link and a
connection to the RAID storage system. The remote execution link is a network connection to another
PC to allow you to execute RAID Manager functions remotely. The connection between the RAID
Manager instance and the storage system illustrates the connection between the RAID Manager
software on the host and the command device. The command device accepts RAID Manager
commands and communicates read and write I/Os between the host and the volumes on the
storage system. The host does not communicate RAID Manager commands directly to the volumes
on the storage system -- the RAID Manager commands always go through the command device.
RAID Manager instance components on the host server 21