HP Hitachi Dynamic Link Manager Software - Manual (Page 717)

A. Notes on Linux Commands and Files
693
commands show little difference before and after HDLM installation.
Table A-1: Examples of Linux Command Execution Times
# 1
CPU: Pentium III 1.4 GHz x 2
Memory: 1 GB
Connection between host and storage systems: 64 LU
x 2 paths (total 128 paths)
# 2
CPU: Xeon 2.0GHz x 2
Memory: 2 GB
Connection between host and storage systems: 64 LU
x 2 paths (total 128 paths)
A.3 Notes on the iostat Command
If an HDLM device is not specified for the
iostat
command, the HDLM device will
not be displayed. Information about an HDLM device is displayed only when the
HDLM device is specified for the
iostat
command (in such case as
iostat -x /
dev/sddlmaa
). The information (CPU or I/O statistics) displayed for the HDLM
device is always
0
, and the actual value is displayed for each SCSI device that
conforms to the HDLM device.
If you are going to obtain information about an HDLM device, perform calculations
by using the value of a SCSI device that conforms to the HDLM device. The following
is an example of executing the
iostat
command.
Linux
commands
Time
Example 1 #1 Example 2 #2
Before HDLM
installation
After HDLM
installation
Before HDLM
installation
After HDLM
installation
lvmdiskscan 6.1 sec 19.6 sec 3.8 sec 10.6 sec
pvscan 2.6 sec 12.6 sec 1.5 sec 5.2 sec