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

38 Chapter 2 HDLM Functions
Figure 2.13 shows the action for intermittent error monitoring when an intermittent error
does not occur. In this example, the path is determined to have an intermittent error if the
error occurs three or more times in 30 minutes. The event occurring in one path is described
on the time arrow.
Figure 2.13 Action When an Intermittent Error does not Occur in the Path
The number of times that the error is to occur is counted when an error occurs. As shown in
Figure 2.13, normally the number of times that the error is to occur is counted each time an
error occurs after the path is recovered online by automatic failback during intermittent
error monitoring. However, if all the paths connected to the LU are in Offline(E), Online(E),
or Offline(C) status due to disconnection of the paths or other reasons, the path is not
recovered online by automatic failback. If I/O operations are continuously issued to such a
LU, the number of times that the error is to occur might be counted even if the path is not
placed online. If the number of times that the error is to occur reaches the specified value,
the path is determined to have an intermittent error. In such a case, remove the cause of
the error, and then manually place the path online.
2.8.3.3 When Conditions for an Intermittent Error Change During Error Monitoring
When the conditions (error monitoring interval and the number of times that the error is to
occur) for an intermittent error are changed during error monitoring, the number of errors
and the time that has passed since the error monitoring started are reset to 0. The error
monitoring does not finish and resumes from the time the conditions are changed.
When you change the conditions outside the error monitoring time, at the time the path is
recovered from the error by using automatic failback, the error monitoring starts with the
changed conditions.
Figure 2.14 shows the action for intermittent error monitoring when the conditions for an
intermittent error are changed during error monitoring. In this example, the conditions have
been changed from 3 or more errors in 30 minutes, to 3 or more errors in 40 minutes. The
events occurring in one path are written on the time arrow.