HP XP7 Storage - Manual (Page 38)

Note:
If there is a path failure immediately after a path is placed offline by using
the dlnkmgr command, Offline(C) might change to Offline(E). If an offline
operation was performed, wait for a fixed period of time (about 2
minute), check the path status by using the dlnkmgr command, and
make sure that the status has changed to Offline(C). If it is Offline(E),
retry the offline operation.
Monitoring Intermittent Errors
An intermittent error refers to an error that occurs irregularly because of
something like a loose cable. In the event of an intermittent error, automatic
failback will repeatedly occur causing I/O performance to drop. To prevent
this from happening, HDLM can automatically remove the path where an
intermittent error is occurring from the paths that are subject to automatic
failbacks. This process is called intermittent error monitoring.
A path in which an error occurs a specified number of times within a specified
interval is determined to have an intermittent error. The path where an
intermittent error occurs remains in error status until the user executes the
HDLM command's online operation to place the path back to online.
Automatic failbacks are not performed for such paths. This status is referred
to as the not subject to auto failback status.
Checking Intermittent Errors
You can check the paths in which intermittent errors have occurred by
viewing the execution results of the HDLM command's view operation.
For details on the view operation, see view (Displays Information) on page
6-25 .
Setting Up Intermittent Error Monitoring
When you set up the intermittent error monitoring function, first specify
whether to enable or disable the function. When you enable the intermittent
error monitoring function, specify the following monitoring conditions: the
error monitoring interval, and the number of times that the error needs to
occur. If you enable the intermittent error monitoring function and an error
occurs on a particular path the specified number of times within the specified
error monitoring interval (in minutes), then an intermittent error will occur on
the path.
You can set up intermittent error monitoring by executing the dlnkmgr
command's set operation.
For details on how to configure intermittent error monitoring, see set (Sets
Up the Operating Environment) on page 6-16 .
2-20
HDLM Functions
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