topic Re: FC disks performance problem in Disk Enclosures

FC disks performance problem

Alberto Tagliaferri — Tue, 19 Dec 2000 17:32:15 GMT

I'm having performance problems on several of my hp-ux boxes accesing EMCs arrays (SAN FC-AL). Without any identified change, I/O performance on fs. over EMC disks has become poor.
I'd like to find out if the problem is on the disk arrarys, SAN or UX box. Can I use "fcmsutil stat" info to help with this? Anyone could guide on what to look at?

Thanks in advance,

Re: FC disks performance problem

Alexander M. Ermes — Thu, 21 Dec 2000 07:29:27 GMT

Hi Alberto.
Use the sar command to collect data and then find the bottleneck.

# sar
0 * * * * /usr/lbin/sa/sa1
20,40 * * * * /usr/lbin/sa/sa1
5 23 * * * /usr/lbin/sa/sa2 -s 00:00 -e 23:59 -i 900 -A

rgds
Alexander M. Ermes

Re: FC disks performance problem

Ovidiu D. Raita — Sun, 31 Dec 2000 03:12:33 GMT

A month ago a coworker of mine faced performance degradation of his FC access to EMC box.

Resolution .... Guess what ?

The EMC support eng enabled tracing on all the disks without telling and forgot to disable them. It took them 4 days to return back to normal. Some time sh.. happens.

It was just a thought :)

You might have a bad EMC disk of fibre. Better change the fibers if you can and ask then ask EMC support for help.

Happy New Year,
Ovidiu