HP NonStop G-Series - Manual (Page 21)

ServerNet Nomadic Disk Overview
ServerNet Nomadic Disk (Release 2) User’s Guide — 523968-001
1 -3
Data Paths and Disk Drive Ownership Before a
Switchover
Data Paths and Disk Drive Ownership Before a Switchover
Figure 1-1 illustrates the active data paths to the disk drives before a switchover in a
two-node configuration.
•
The thick solid lines designate active data paths, which are between the primary
node \PRI and the primary disk drives and mirror disk drives. The primary disk
drives are located with and owned by the primary node. The remote mirror disk
drives are owned by primary node, but located with the backup node \BCK for fault
tolerance.
Figure 1-1. Remote Mirroring Before Switchover
VST201.vsd
MSEB
MSEB
MSEB
MSEB
\PRI I/O
Enclosure
46xx Disk Drives**
\BCK I/O
Enclosure
46xx Disk Drives**
Primary
Disks
Mirror
Disks
Local
System
Remote
System
\PRI
Processor
Enclosure
\BCK
Processor
Enclosure
IOMF 2 IOMF 2 IOMF 2 IOMF 2
Switch
Cards
Switch
Cards
** Nomadic Disk subsystem is configured with either 46xx internal disk drives or
45xx external disk drives, but not both.