On backup node \bck, Unplanned switchovers – HP NonStop G-Series User Manual
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Switchovers
ServerNet Nomadic Disk (Release 2) User’s Guide — 523968-001
5 -6
On Backup Node \BCK
On Backup Node \BCK
1. If you are not using the Nomadic Disk Manager:
a. Change the fiber-optic switches at the backup node to the opposite position as
Moving the Fiber Optic Switches to the Opposite Position
b. Use the SWCI STATUS command to verify that switch modules are in the
correct position.
SWCI $SWITCH1.#PRI> STATUS
c.
Use the SCF START DISK command to start the nomadic volumes that were
switched from the primary node.
-> START DISK $nomadicvol, $nomadicvol
2. If you are using the Nomadic Disk Manager:
a. At a TACL prompt, log on to \BCK as the super ID and start the Nomadic Disk
Manager.
> NOMADIC
b. Use the TAKE command to assume ownership of the Nomadic volumes from
\PRI.
1 ND> TAKE DATA
c.
Wait for the TAKE command to finish.
d. Make sure all disk paths are up. If they are not up, use the RESET and UP
commands to make all paths up.
3. Start applications that access data on the Nomadic volumes.
4. Notify Network Services the applications are ready for processing.
5. Network Services finishes switchover of incoming transactions and normal
processing resumes.
Unplanned Switchovers
When a primary node fails, you must perform an unplanned switchover to continue
operations on the backup node. Plan for the possibility of an unplanned switchover
before a primary node failure occurs. For an example of how the switch modules
support the disk drives after switchover, see
Data Paths and Disk Drive Ownership
An example of an unplanned switchover from the primary node to the backup node
occurs when the primary node \PRI loses all power; the operator at the backup node is
then notified of the outage. The following procedure performs an unplanned switchover
of the primary node applications.