HP NonStop G-Series - Manual (Page 44)

Installing and Configuring the Nomadic Disk
Manager
ServerNet Nomadic Disk (Release 2) User’s Guide — 523968-001
3- 10
Nomadic Disk Manager Configuration Statements
Considerations
•
Although spare segments are used with spare disk modules in NonStop K-series
servers, spare disk modules are not currently supported for the ServerNet
Nomadic Disk subsystem; therefore, the SPARE parameter should not be used
with NonStop S-series servers.
•
A segment represents either the internal 46xx disk drives in a pair of I/O
enclosures or a pair of up to eight 455mod8 disk modules containing external 45xx
disk drives:
°
One set of internal 46xx disk drives (or external 45xx disk drives) is located at
the primary node and contains the primary volumes.
°
The other set of internal or external disk drives is located at the backup node
and contains the mirror volumes.
•
A segment of internal 46xx disk drives can have from 1 to 16 mirrored volumes; a
segment of external 45xx disk drives can have from 1 to 64 mirrored volumes.
•
The attributes of the segment must have been previously specified by SET PATH
and SET VOL statements. The SET PATH and SET VOL statements modify a
segment template; the ADD SEGMENT statement uses the data in that segment
template. The ADD SEGMENT statement implicitly resets the segment template.
•
All data segments are normally switched between nodes as a group. This feature
can be overridden, but an override should be attempted only in an emergency.