HiCommand Dynamic Link Manager (HDLM) for Windows Systems User's Guide (HIT5201-96001, January 2008)
228 Chapter 7 Command Reference
The explanation for the following sub-parameter describes how to specify the checking
interval.
To specify the checking interval between path health checks (in minutes), use -intvl
checking-interval. Specify a value from 1 to 1440 minutes depending on the user
environment. When you change the checking interval, the new setting takes effect
immediately. When the checking interval is shortened and the checking interval after the
change (from the end of the previous path health check) has already elapsed, the path
health check will start immediately.
The path health check interval setting remains stored in the system even if you disable the
function by changing the setting of path health checking to off. Therefore, when you re-
enable path health checking and do not change the interval, path health checking is
executed at the interval stored in the system.
To enable or disable automatic failback, use -afb {on [-intvl checking-
interval]|off}.
on: Enabled
off: Disabled
Enabling automatic failback may automatically place online those paths 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, path status alternates
between the online and offline status frequently, so I/O performance might deteriorate.
Automatic failback is executed in the following paths:
Path where an error occurred and for which the KAPL08022-E message was displayed.
Path where an error occurred at the startup of the HDLM manager.
To prevent an intermittent error from deteriorating I/O performance, we recommend that
you also enable intermittent error monitoring when enabling automatic failback.
Intermittent error monitoring is specifiable only when automatic failback is enabled.
See
Table 7.5 for the relationship between automatic failback and intermittent error
monitoring.
When you specify on, specify the checking interval of path status by specifying the
parameter immediately following on. If you do not specify a checking interval, path status is
checked in the following interval:
When the checking interval has not been specified before: Every minute (default
setting).
When the checking interval has been specified before: The interval used in the last time.
The explanation for the following sub-parameter describes how to specify the interval
between path status checks.