Hitachi Dynamic Link Manager, User Manual, Page: 443 / 746

6. Command Reference
419
The explanation for the following sub-parameter describes how to specify the
checking interval.
-intvl
checking-interval
Specify the checking interval between path health checks. 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 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 paths online that were
intentionally placed offline (for example, paths placed offline for maintenance
work).
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 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 Operations 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