HP Hitachi Dynamic Link Manager Software User Manual
Page 255
6. Command Reference
231
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).
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 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
will be checked in the following way:
• When the checking interval has not been specified before:
Every 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. Specify an interval appropriate for your operating
environment.
If intermittent error monitoring is
on
and the number of times that the error
is to occur is set to a value of 2 or more, the following condition must be
satisfied: