100% Disk utilization

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casey - 26 Mar 2004 19:42 GMT

RSAM Version 5.05.UC2 -- On-Line -- Up 11 days 21:17:56 --
30944 Kbytes

Can you spot why I see at OS level 100% Disk ?

Profile
dskreads pagreads bufreads %cached dskwrits pagwrits
bufwrits %cached
13650367 19452123 1757997773 99.22 647795 2658829
144121943 99.55

isamtot open start read write rewrite delete
commit rollbk
1085291621 9035411 70243722 476132825 38499036 4037589
1251898 19002272 176

ovtbls ovlock ovuser ovbuff usercpu syscpu
numckpts flushes
0 0 73 0 42907.59 3372.75 6522
16895

bufwaits lokwaits lockreqs deadlks dltouts lchwaits
ckpwaits compress
95966 135 1614122389 1 0 2063 5962
8418822

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Paul Watson - 26 Mar 2004 20:38 GMT

It might be legit.

Have a look at tbstat -u for users with large disk activity

> RSAM Version 5.05.UC2 -- On-Line -- Up 11 days 21:17:56 --
> 30944 Kbytes
[quoted text clipped - 21 lines]
> 95966 135 1614122389 1 0 2063 5962
> 8418822

Signature

Paul Watson #
Oninit Ltd # Growing old is mandatory
Tel: +44 1436 672201 # Growing up is optional
Fax: +44 1436 678693 #
Mob: +44 7818 003457 #
www.oninit.com #

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casey - 26 Mar 2004 21:23 GMT

By far, the highest I/O are report queries.

> It might be legit.
>
[quoted text clipped - 25 lines]
> > 95966 135 1614122389 1 0 2063 5962
> > 8418822

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Paul Watson - 27 Mar 2004 00:32 GMT

I'd suspect a missing index, set explain on and look for
sequential scans

> By far, the highest I/O are report queries.
>
[quoted text clipped - 40 lines]
> > Mob: +44 7818 003457 #
> > www.oninit.com #

Signature

Paul Watson #
Oninit Ltd # Growing old is mandatory
Tel: +44 1436 672201 # Growing up is optional
Fax: +44 1436 678693 #
Mob: +44 7818 003457 #
www.oninit.com #

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Art S. Kagel - 29 Mar 2004 15:54 GMT

> By far, the highest I/O are report queries.

If those are 4GL reports, look for ORDER BY sections in the report function
that are not REPORT BY ... EXTERNAL. If you can put the ORDER BY criteria
into the query supplying the data and make the report's ORDER BY be EXTERNAL
that will reduce IO's not reported by the engine hugely.

Art S. Kagel

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casey - 29 Mar 2004 16:10 GMT

> > By far, the highest I/O are report queries.
> >
[quoted text clipped - 4 lines]
>
> Art S. Kagel

Art, thanks, great suggestion!

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