HiCommand Dynamic Link Manager (HDLM) for Windows Systems User's Guide (HIT5201-96001, January 2008)

72 Chapter 3 Creating an HDLM Environment
3.5.2.4 Settings for Intermittent Error Monitoring
Intermittent error monitoring is specifiable only when automatic failback is enabled. To
prevent an intermittent error from reducing I/O performance, we recommend that you
monitor intermittent errors when automatic failback is enabled.
When intermittent error monitoring is enabled, you can specify intermittent error conditions
(the conditions used by the system to determine whether an intermittent error is occurring).
The default value for the intermittent error monitoring interval is 30. The default value for
the number of error occurrences is 3.
The system assumes that an intermittent error is occurring if the specified number of times
that the error is to occur is reached during the monitoring interval (from the time that the
monitoring interval starts, until the specified interval ends). A path that is assumed to have
an intermittent error is excluded from automatic failback. Intermittent error monitoring
starts when the path is recovered from the error by using automatic failback. Monitoring is
performed on individual paths.
When a value of 2 or more is specified in number of times, make sure that the condition
shown in section
3.5.2.3 is satisfied.
To determine whether a path is ineligible for automatic failback, you can use the results of
the dlnkmgr command's view operation or the Path List view of the HDLM GUI.
 Setting by using the Options window.
To enable intermittent error monitoring, specify ON. To disable intermittent error
monitoring, specify OFF. When you specify ON, you can specify intermittent error
conditions (the conditions used by the system to determine whether an intermittent
error is occurring) in Monitoring interval and Number of times.
 Setting by using the set operation.
The following shows an example of executing the command to set the error log
collection level.
>dlnkmgr set -iem on -intvl 20 -iemnum 2
on specifies that intermittent error monitoring is to be used. To disable intermittent
error monitoring, specify off. When you set this parameter to on, you can specify
intermittent error conditions (the conditions used by the system to determine whether
an intermittent error is occurring) by using the -intvl and -iemnum parameters.
Specify the monitoring interval for an intermittent error in the -intvl parameter, and
the number of times that the error is to occur in the -iemnum parameter. When these
parameters are omitted and 3 or more errors occur within 30 minutes, the system
assumes that an intermittent error is occurring.