HP 3000 Manuals HP 3000 Manuals
Chapter 3 Performing an SPU Switchover
This chapter provides procedures for system operators to switch over
switchable volume sets from a home SPU to an alternate SPU. Common
reasons for switching over to the alternate SPU are as follows:
* The home SPU experienced a hardware failure necessitating a
temporary emergency switchover of switchable volume sets to the
alternate SPU.
* Scheduled maintenance, configuration changes, or load balancing
necessitated a temporary scheduled switchover of switchable volume
sets to the alternate SPU.
After you install and configure for SPU Switchover/XL, a system status
message is sent between the two systems. If a system detects that its
partner no longer responds to the system status message, a message is
displayed on the system's console. For example, system Alpha is not
responding. The following message is displayed on system Beta:
/00:00/nn/ACKNOWLEDGE SYSTEM ALPHA NOT RESPONDING.
PLEASE CHECK ALPHA (Y/N)?
This message continues to be displayed until the operator stops the
message by replying to it. At this point, the operator decides whether
or not to start the switchover. If the operator decides to switch over,
the following occurs:
1. The operator can stop applications and terminate sessions on the
alternate system, as needed, to prevent performance problems from
occurring once the applications from the home system are started
on the alternate system.
2. The operator executes the SWITCHOVER command on the alternate
system. This command opens the switchable volume sets that were
on the home system. A message is displayed after each switchable
volume set is switched over to the alternate system. When all
switchable volume sets are mounted, switchover is complete.
3. The applications that were on the home system can now be restarted
on the alternate system by the operator.