Re: Disk Percent Busy, out of whack??

Here's another sample from a different system. 2:32 time frame:

5.1 45.8 7.9 .0 45.8 .0 7.9 0
5.1 46.7 8.1 .9 45.8 16.0 7.9 2
5.1 46.6 8.0 .9 45.7 16.0 7.9 2
5.1 46.7 8.0 .9 45.8 16.0 7.9 100
4.6 61.9 8.0 .9 61.0 16.0 7.9 2
4.6 62.0 8.0 .9 61.0 16.0 7.9 2

This one is SCSI Disks i 7.1 one RAID set here. First four have stripe data, last two do not. Deleting data from the IFS - Very few VERY Large objects (> 20GB each)

Odd but I guess not really a problem, just odd.

- Larry "DrFranken" Bolhuis

www.frankeni.com
www.iDevCloud.com
www.iInTheCloud.com

On 9/30/2014 9:53 PM, DrFranken wrote:

I watched it for some time and even for 5 minutes it was over 30% for
the one drive and 1% for the others.

I reset at 5 minutes and watched for several more observing the same
activity.

Once the CRTNWSSTG was completed and disk I/O fell to zero then when I
started using the iASP then it 'seemed' normal.

I do have the navigator monitors running and will further investigate on
THursday when I am on site there again.

I think the biggest question in my head is how is that % Busy
calculated? Clearly it's not just reads and writes counters times the
size of the reads and writes blocks divided into some theoretical
maximum I/O for the type of drive. And this itself isn't surprising. I'm
guessing that seek distance and write pattern contribute to the drive
busyness. Just doesn't seem like it would be THAT different!


- Larry "DrFranken" Bolhuis

www.frankeni.com
www.iDevCloud.com
www.iInTheCloud.com

On 9/30/2014 5:37 PM, Sue Baker wrote:

DrFranken <midrange@xxxxxxxxxxxx> wrote on Tue, 30 Sep 2014
18:25:48 GMT:

Elapsed time: 00:01:00

I think the key here is the elapsed time. We have said for
generations that anything less than about 5 minutes is likely to
produce wonky statistics.

I don't suppose you've set up the Navigator for i monitors or
have collection services set at 1 minute intervals to go back
and see if it's a WRKDSKSTS anomaly or something else?