disk performance

[Coy Trosclair]

Group,

Hi - I need some help. My configuration is:

Two N-class machines connected via fiber (and switches) to 3 va7100 enclosures. We are running measureware and glance.

Here's what I want to know:
How fast my disks are performing. In the same terms as HP's product info. if possible. HP states that the va7100 is capable of 90mb per second throughput, so it would be nice to see what my throughput currently is on my luns. I have looked at measureware and I'm pulling some stats, but it's nowhere near the 90mb level, so I think maybe either I'm pulling the wrong stats, or doing something else wrong.

Obviously, I have several luns built on these arrays, so someway to check the throughput would be great.

thanks,

c

[Sandip Ghosh]

The speed what they used to mention is Mega Bit per second no Mega Bytes per Sec. So whatever output you are getting multiply that with 8. It will be around that.

Sandip

[A. Clay Stephenson]

No the specs are in MBytes per second but the problem is that it is very difficult to push that much data to your array over a single channel.

About as good as you are going to do is something like this as a read test:

dd if=/dev/vgxx/rlvol7 (or /u01/myfile) of=/dev/null bs=4k count=1000000

(You should vary the bs (blocksize)).

A write test might be
dd if=/dev/zero of=/u01/myfile bs=4k count=1000000

If you don't have a /dev/zero device node to supply an unlimited stream of NUL's, you can create one thusly:

mknod /dev/zero c 3 0x000003
chmod /dev/zero 444

You can also place the timex command in front of the dd's to get some measure of throughput though Glance is better.