Repairs; Rerouting To The Primary Path After Failover - HP e3000 MPE/iX Manual

Recovering From a Failover

Repairs

Repairs
The repair of Hardware failures on disk array products, especially those
connected to a Fibre Channel network, can be a complex activity. Normal
Hardware troubleshooting techniques must be followed to determine the source
of the failover event. This may include examination of system or device error
logs. The methods and procedures for these troubleshooting activities are
outside the scope of the HAFO product and this manual. If a failover event
occurs for which you cannot determine the cause, you should place a call with
your Support provider as if the I/O path failed.
Repairs to the failed component in the data path should be performed as soon as
possible to avoid a double failure on the HA array. Remember that while you are
running on the alternate path, you are NOT protected from further path failures.
It should also be noted that the greater the number of Ldevs routed through a
single device adapter card, the greater the I/O workload and possible I/O
performance degradation. In some cases degradation may be severe enough to
trigger "timeout" failover events on paths that don't otherwise have a problem.
HAFO does not in anyway change the replacement procedures for hardware
components. That is, some devices, such as system Host Bus Adaptors, will still
require a system shutdown and power cycle to replace. However, HAFO does
have the effect of turning an unplanned failure of a component into a future
system maintenance activity.
High availability arrays like the HP SureStore XP1024 have many redundant
subsystems including dual controllers. If an array controller is the source
problem for data path failure, the controller may be replaced "hot swapped"
while the system and array are online. It is up to your System Support provider
to determine which activities can be performed without a System Reboot.

Rerouting to the Primary Path After Failover

If a repair does not require re-booting, such as after a "hot swap" replacement of
the array controller, the
I/O to the other path.
"Validated" status.
If a repair requires the system be shut down and re-booted, I/O will default to all
available configured primary paths.
scenario.
The six-step validation process documented in the
"Configuration," occurs when
booted.
42
command should be invoked.
GONEXT
should only be performed if the other path shows
GONEXT
GONEXT
is invoked or when the system is re-
GONEXT
GONEXT
does not need to be invoked in this
section of Chapter 4,
DOHA
reroutes