topic Disk perfomance in Operating System - HP-UX

Disk perfomance

Arun.hpunixadmin — Wed, 22 Sep 2010 16:33:48 GMT

How can we confirm whether a disk got perfomance problem and need to be replaced?

Re: Disk perfomance

Bill Hassell — Thu, 23 Sep 2010 02:35:06 GMT

If you have disk problems, they will be logged in the file /var/adm/syslog/syslog.log, and your programs will not run or will abort with error messages.

Re: Disk perfomance

Abid Iqbal — Thu, 23 Sep 2010 06:22:58 GMT

Also you can monitor it with sar.
man sar
and use it.

Re: Disk perfomance

Chandrahasa s — Thu, 23 Sep 2010 15:13:10 GMT

Hi,

For confirming issue with disk you can follow following steps,

a)Go to glance and verify how much disk utilization is.
B)iostat 2 5
verify disk utilization here
c) sar -d 2 10

Chandra

Re: Disk perfomance

Arun.hpunixadmin — Sun, 26 Sep 2010 05:51:23 GMT

Thanks for your reply.My question is,
In which parmeter from a particular command can be used to confirm the particular disk needs to be replaced? Even i know these all the command can be used to check but how to confirm?

If i have 50 LUN and it is very diffuclt for me to check and find out from which disk the perfomance get degraded.So is there any easy way to detect perfomance issue?

Re: Disk perfomance

chris huys_4 — Sun, 26 Sep 2010 20:11:21 GMT

Hi,

Only defective disks gets replaced. Disks with "performance problems", that are not caused by a hardware defect, will never get replaced as not the disk is the cause of the performance problem, but something else.

So there is no "command" or "option" to find "performance problem disks that needs to be replaced".

Greetz,
Chris

Re: Disk perfomance

Bill Hassell — Sun, 26 Sep 2010 21:30:13 GMT

All of us want disks that will report problems before they fail. Unlike tires that wear out or bearing that get hot or squeal before they fail, disks usually go bad quickly. They are both electronic and mechanical. Electronics almost always fails immediately and the flying head that gathers the data might return a few recoverable errors before crashing. While the inability to communicate might be a performance problem, the bottom line is that you never run an important computer with disk mirroring of some sort. Make sure your online diagnostics and patches are up to date and that email is enabled to send you notifications of system problems.

Re: Disk perfomance

SoorajCleris — Mon, 27 Sep 2010 02:50:43 GMT

Hi,

sar -d

will give you most utilized 5 disks.
If your disk is really have problem it will have all high values. ( mostly it comes in your first 5)

always check if your disk , busy and hight avwait parameters.

Regards,
Sooraj