HP NonStop G-Series - Manual (Page 20)

ServerNet Nomadic Disk Overview
ServerNet Nomadic Disk User’s Guide— 425485-001
1 -4
Data Paths and Disk Drive Ownership After a
Switchover
Data Paths and Disk Drive Ownership After a Switchover
To manage outages, both the primary disk drives and remotely located mirror disk drives
can be switched to the backup node. When a outage brings down the primary node, the
ownership of the disk drives can be switched to \BCK. After a switchover, the active
data paths are as shown in
Figure 1-2 .
•
The thick solid lines designate active data paths, which are between the backup node
and the primary and mirror disk drives. The primary disk drives, which are located
with the primary node \PRI, are now owned by the backup node \BCK. The mirror
disk drives are also now owned by the backup node.
•
The thinner lines indicate inactive data paths, which are between the primary node
and the primary and mirror disk drives.
Figure 1-2. Remote Mirroring After a Switchover
Primary Node
\PRI
MSEB
MSEB
SNDA
SNDA
Processor
Enclosure
MSEB
MSEB
SNDA
SNDA
Processor
Enclosure
SNDA
SNDA
\PRI I/O
Enclosure
IOMF 2
IOMF 2
SNDA
SNDA
\BCK I/O
Enclosure
IOMF 2
IOMF 2
Switch
Module
1
2
3
4
1
2
3
4
Mirror
Disks
Backup Node
\BCK
1
2
3
4
Switch
Module
1
2
3
4
Primary
Disks
VST101.vsd