HP XP Racks User Manual
Page 228
health check) has already elapsed, the path health check will start
over.
The path health check interval setting remains stored in the system
even if you disable the function by changing the path health checking
to off. Therefore, when you re-enable path health checking and do
not change the interval, the path health interval stored in the system
is used.
-afb {on [-intvl checking-interval]|off}
Enables or disables automatic failback.
on: Enabled
off: Disabled
Enabling automatic failbacks might automatically place online paths online
that were intentionally placed offline (for example, paths placed offline for
maintenance work).
If you want to prevent such paths from automatically being placed online,
disable this function. When intermittent errors occur in paths or storage
systems, statuses of paths alternates between the online and offline
status frequently, thus decreasing I/O performance.
Automatic failbacks are performed on the following types of paths:
¢
Paths where an error occurred and for which the KAPL08022-E
message was displayed.
¢
Path where an error occurred during the startup of the HDLM
manager.
To prevent intermittent errors from deteriorating I/O performance, we
recommend that you also enable intermittent error monitoring when the
automatic failback function is enabled. Intermittent error monitoring is
specifiable only when automatic failbacks are enabled.
See
Table 6-5 Relationship Between the Setting for the Automatic
Failback Function and Intermittent Error Monitoring and the Executable
for the relationship between automatic
failbacks and intermittent error monitoring.
When you specify on, specify the checking interval by specifying the
parameter immediately following on. If you do not specify a checking
interval, path statuses will be checked in the following way:
¢
When the checking interval has not been specified before:
Every 60 minute (default setting)
¢
When the checking interval has been specified before:
The previously used interval
The explanation for the following sub-parameter describes how to specify
the interval between path status checks.
-intvl checking-interval
Specify the interval between path status checks. Specify a value from
1 to 1440 minutes. The default is 60. Specify an interval appropriate
for your operating environment.
6-22
Command Reference
Hitachi Dynamic Link Manager User Guide for AIX®