Notes On Using Hdlm; Displaying Path Information; When A Path Error Is Detected; Iostat Command - Hitachi XP P9500 User Manual

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.

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.

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
Errors by Using Path Health Checking on page

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.
4-2
HDLM Operation
Hitachi Dynamic Link Manager User Guide (for Solaris(R))
Detecting
2-27.