Timeout Parameter; Addconf Limitations - HP e3000 MPE/iX Manual

Timeout Parameter

The Timeout parameter is used to allow or disallow failovers caused by slow or
slightly unresponsive disk arrays. Timeout defaults to "true", which gives the
best protection but may give "false" failovers under heavy I/O loads. If it has
been determined that the observed failovers are "false" failovers and are caused
by heavy I/O traffic, setting the timeout parameter to "false" may reduce the
"false" failovers but it also reduces the protection offered by HAFO.
Systems administrators who see many timeout conditions may need to consult
NOTE
with Disk Array "storage" specialists to determine the source of these
performance limitations. As disk arrays are often shared by several systems the
diagnosis of these problems can be very difficult. It is possible that the only
solution to a performance issue is the purchase of additional hardware. This is
why it is very important to understand the I/O "environment" of an MPE/iX
system before adding HAFO.

ADDCONF limitations

The hardware must be in place, configured through SYSGEN, and initialized at
system boot time before issuing this command. The Ldev specified must be
mounted in the MEMBER or MASTER state. Once added using
primary and alternate paths are checked for availability against internal system
I/O tables. If the Ldev cannot be accessed through both paths specified, then an
error will be issued and the Ldev will NOT be added to the configuration.
Although this makes it much more difficult to make configuration mistakes, it
also prohibits the creation of HAFO configurations for other systems that are
different than the present system.
Because HAFO works in pairs, the very first successful
NOTE
is entered (and applied, see the
paths. All Ldevs on the primary path specified must then be configured to
failover to the alternate path specified. Further, all the Ldevs on the alternate
path specified must be configured to failover to the primary path specified in the
first command specifying these paths. See Figure 2-1.
ADDCONF
command) links the HBAs on those two
DOHA
Configuration
ADDCONF (ad)
, the
ADDCONF
command that
ADDCONF
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