HP Hitachi Dynamic Link Manager Software - Manual (Page 290)

4. HDLM Operation
268
4.1 Notes on Using HDLM
This section explains the 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 path IDs displayed by using the
dlnkmgr
command's
view
operation differ
depending on the order in which paths were detected when the host started. For
this reason, you should always use the path name to specify a path.
• When displaying the path status for a new LU that was dynamically added by
executing the
dlmcfgmgr
utility for managing the HDLM configuration, a
disconnected path might be displayed as
Online(E)
even though another online
path is connected to the LU.
If this situation occurs, perform the online operation for the path displayed as
Online(E)
, and then update the path status.
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 on
path health checking, see 2.10 Detecting Errors by Using Path Health Checking.
4.1.3 iostat Command
The
iostat
command lists devices that are not represented by sd or ssd device logical
device file names, but by sd or ssd device types and instance numbers.
By executing the
dlnkmgr
command's
view -drv
operation, you can obtain the
mapping between the logical device file names of HDLM devices and the
combinations of sd or ssd device types and instance numbers listed by the
iostat
command.
Shown below are examples of output from the
iostat
command and the
dlnkmgr
command's
view -drv
operation. It is assumed that one LU and two paths exist. In the
lists,
c0t6d0
and
c1t12d0
represent a DVD-ROM drive and a built-in disk,
respectively.