Hitachi Dynamic Link Manager Software Users Guide for AIX

Table Of Contents
As shown in Figure 2-12 What Will Happen When an Intermittent Error Does
Not Occur on a Path on page 2-26, normally the count for the number of
times that an error occurs is started after the path is first recovered from an
error by using the automatic failback function. However, if all the paths
connected to the LU are in the Offline(E), Online(E), or Offline(C) status
(which is due to the disconnection of the paths or some other reason), the
paths will not be recovered and put back online by using the automatic
failback function. If I/O operations are continuously being issued to such an
LU, the count for the number of times that the error occurs might be started
even though the path will not be placed online. If the number of times that
the error occurs 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.
When the conditions for an intermittent error are changed during error
monitoring
When the conditions for an intermittent error are changed during error
monitoring, the number of errors and the amount of time that has passed
since the error monitoring started are both reset to 0. As such, the error
monitoring will not finish, and it will start over by using the new conditions.
If the conditions are changed while error monitoring is not being performed,
error monitoring will start up again and use the updated conditions after any
given path is recovered from an error by performing an automatic failback.
The figure below shows the action taken when the conditions for an
intermittent error are changed during intermittent error monitoring. For 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 that occur are
described by using the time arrows.
Figure 2-13 What Will Happen When Conditions Are Changed During Error
Monitoring
HDLM Functions
2-27
Hitachi Dynamic Link Manager (for AIX) User Guide