HP Hitachi Dynamic Link Manager Software - Manual (Page 200)

4. HDLM Operation
178
4.1 Notes on Using HDLM
This section provides notes on using HDLM and using the environment in which
HDLM is installed. Make sure that you read this section.
4.1.1 Displaying Path Information
The
AutoPATH_ID
that is displayed during the HDLM
dlnkmgr
command's
view
operation differs depending on the order in which paths are detected when the host
starts. For this reason, you should always use the path name to specify a path.
4.1.2 When a Path Error Is Detected
When a path error is detected by HDLM, you must immediately resolve the error and
restore the path.
A check for path errors is performed whenever an I/O is issued. If there are any paths
through which I/O is not normally issued, such as a non-owner path, you should enable
path health checking in order to detect errors even when there is no I/O. For details
about path health checking, see 2.9 Detecting errors by using path health checking.
When a path is in an error state and the interval specified for a path health check or a
failover has been reached and you execute any of the following, the response time of
the processing might slow down while the path health check or failover is being
executed:
„ HDLM command
„ HDLM utility
„ OS commands for operating volume groups
„ mount/umount
command
„ cfgmgr
command
„ mkdev
command
„ rmdev
command
„ chdev
command
When a path is in an error state, if you perform the online operation of the HDLM
command with the
-s
parameter, it might take a long time for the command processing
to finish.
When a path is in an error state and you want to place all paths or several paths online
at the same time, we recommend that you execute the command without specifying the
-s
parameter. If you do this and a path cannot be placed online, a message confirming
that you want to continue the processing is displayed. If you enter
n
in response to this