HP NonStop G-Series - Manual (Page 27)

Nomadic Disk Hardware and Software
ServerNet Nomadic Disk (Release 2) User’s Guide — 523968-001
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Nomadic Disk Hardware
SWCI requests information about the switch module or changes the state of individual
switches. SWCI sends each command to the switch controller card (SCC) of the switch
module and then reports the results of the command execution back to you. The SCC
controls all switch cards in the switch module. The SWCI software is located on the
$SYSTEM.SYS
nn subvolume.
Nomadic Disk Hardware
This section introduces the Nomadic disk system hardware configurations.
The hardware required for your Nomadic disk configuration depends on whether
internal or external disks are used for mirroring, the distance between the host node
and remote disk modules, and whether you have a one- or two-node configuration (a
two-node configuration requires fiber-optic switching).
Internal Disk Drive Configuration
Figure 2-1 shows a Nomadic disk system configuration with a single processor
enclosure that mirrors internal disk drives between the primary and backup sites. The
fiber-optic cabling length to the backup site containing the mirror disk drives is limited
to five kilometers maximum.
Note. For more detail on the Nomadic disk hardware than provided in this guide, see the
ServerNet Nomadic Disk (Release 2) Installation and Service Guide.