High DISK Utilization

[Mike_145]

On our SAN I am seeing two of the disk with continual 98% utilization on them through sar command. There are about a 1/2 dozen file systems that have logical volumes assigned extents on these two disk. Is there a way to figure out exactly which logical volumes are the ones being utilized the hardest that we may be able to split them out ?? We do not have glance on this server...

[Mel Burslan]

I am not sure if this program has any value to you, but it may worth to take a look here:

http://hpux.cs.utah.edu/hppd/hpux/X11/Networking/xperfmon-2.8/

it has disk transfer activity monitors as well, even though the tool is catalogued under 'networking' branch of utilities.

Hope it helps

[lawrenzo]

use this command to check for physical disk problems i/o errors

dd if=/dev/rdsk/ of=/dev/null bs=64k

This may show a problem with disk.

[Isralyn Manalac_1]

Hi Mike,

I've attached herewith an Intro to Performance and Tuning. Excerpt for disk utilization: if avwait is bigger than avserv, then there is disk bottleneck. Identifying which logical volumes are utilized the most won't help resolve the issue because the LV may be spread across different disks. Please see attached file for recommendations on improving I/O.

Good luck!

Regards,

Isralyn

[Mike_145]

Mel, when trying to run xperfmon I receive: no /stand/vmunix namelist

[Mel Burslan]

Mike,

I personally have not ever used this utility. I just have heard it being mentioned by another colleague of mine in one of my past jobs. Hence I am not sure what this error message can be related to but, a quick look to the man page on the archive tells me, this applcation needs to be owned and run by root (or at least its suid bit needs to be set) for proper operation.

It might worth trying. Other than that, I don't know what to say. It si so old, its home page pointed from the software archive does not even exist.