AIO VP has more load then KAIO
Petr Pomykacek, on IDS 11.50.FC3 on HP-UX with raw chunks, saw the AIO VP doing far more I/O than the KAIO VPs. Jacques Renaut suggested checking set explain or SPL tracing with onstat -g ioq and -g iof. Everett Mills suggested sorting in filesystem space. Paul M. asked whether KAIO was enabled with KAIOON set, and whether character devices were used. Unresolved.
Auto-generated by Claude from the posts below — may be imperfect; read the full thread.
hi all,
I have only raw chunks on HP-UX, but AIO VP has load more then KAIO. Why ?
Do you have someone any ideas.
thaks
Petr Pomykacek
IBM Informix Dynamic Server Version 11.50.FC3 -- On-Line -- Up 3
days 14:30:41 -- 1694836 Kbytes
AIO I/O vps:class/vp s io/s totalops dskread dskwrite dskcopy wakeups io/wup
errors tempops
kio 0 i 5.1 1576542 643302 933240 0 1942104
0.8 0 0
kio 1 i 5.1 1579674 911754 667920 0 2231189
0.7 0 0
msc 0 i 1.4 442230 0 0 0 431282
1.0 0 442230
!!!! aio 0 i 27.8 8651970 34 8572699 0 8635107
1.0 0 6580 !!!!
aio 1 i 0.1 20548 0 20369 0 26298
0.8 0 0
aio 2 i 0.0 2419 0 2399 0 2949
0.8 0 0
pio 0 i 0.0 0 0 0 0 1
0.0 0 0
lio 0 i 0.0 0 0 0 0 1
0.0 0 0
Hmm, it could be you have set explain turned on, or tracing enabled in a SPL?
You could try looking at onstat -g ioq aio in conjunction with onstat -g iof
to see what files the aio vps are writing too.
Jacques
Hi Jacques,
thanks to the idea. Let me see.
Petr
JACQUES RENAUT wrote:
> Hmm, it could be you have set explain turned on, or tracing enabled in a SPL?
> You could try looking at onstat -g ioq aio in conjunction with onstat -g iof
> to see what files the aio vps are writing too.
>
> Jacques
>
>
>
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> -----Original Message----- > From: ids-bounces@iiug.org [mailto:ids-bounces@iiug.org] On Behalf Of Petr > Pomykacek > Sent: Wednesday, February 11, 2009 3:14 PM > To: ids@iiug.org > Subject: AIO VP has more load then KAIO [14845] > > hi all, > > I have only raw chunks on HP-UX, but AIO VP has load more then KAIO. Why ? > Do you have someone any ideas. > > thaks > > Petr Pomykacek > Snip If you do a lot of sorting in file system space rather than temp dbspaces, that would bump up the processor time on your AIO vp's. --EEM
> -----Original Message----- > From: ids-bounces@iiug.org [mailto:ids-bounces@iiug.org] On Behalf Of > Everett Mills > Sent: Wednesday, February 11, 2009 3:42 PM > To: ids@iiug.org > Subject: RE: AIO VP has more load then KAIO [14849] > > > -----Original Message----- > > From: ids-bounces@iiug.org [mailto:ids-bounces@iiug.org] On Behalf Of > Petr > > Pomykacek > > Sent: Wednesday, February 11, 2009 3:14 PM > > To: ids@iiug.org > > Subject: AIO VP has more load then KAIO [14845] > > > > hi all, > > > > I have only raw chunks on HP-UX, but AIO VP has load more then KAIO. > Why ? > > Do you have someone any ideas. > > > > thaks > > > > Petr Pomykacek > > > Snip > > If you do a lot of sorting in file system space rather than temp > dbspaces, that would bump up the processor time on your AIO vp's. > << snipped >> Since you are running on HP-UX -- did you turn on KAIO? There are certain steps to enable it in the kernel, plus you need to explicitly set the KAIOON environment parameter before bringing up the engine. Finally, are you using the Block devices or the Character devices for your raw chunks? They need to be the Character devices. HTH, Paul M.