os: AIX 6.1
informix: ids11.5.fc6

Before AIX 5.x , To start ids ,It need to run 'mkdev -l aio0'.
But under AIX 6.1, there are two question bothering me.

1. can not enable AIO ,the error message is:
# /usr/sbin/mkdev -l aio0
mkdev: 0514-519 The following device was not found in the customized
device configuration database:
name = 'aio0'
2. Start ids is OK ,though failed to enable AIO.

This is not necessary on AIX 6.1:

www.ibm.com/support/docview.wss?uid=swg21303183

Does "onstat -g iov" show "kio" entries? If so, it is using kernel AIO. Are
you using raw devices?

Regards,
Doug Lawry


"joe" <joeclhua (AT) gmail (DOT) com> wrote

#onstat -g iov

IBM Informix Dynamic Server Version 11.50.FC6 -- On-Line -- Up
00:01:14 -- 501344 Kbytes

AIO I/O vps:
class/vp/id s io/s totalops dskread dskwrite dskcopy wakeups io/
wup errors tempops
fifo 7 0 i 0.0 0 0 0 0 1
0.0 0 0
msc 6 0 i 0.0 1 0 0 0 2
0.5 0 1
aio 5 0 i 2.9 214 19 145 0 214
1.0 0 0
aio 8 1 i 0.0 3 0 3 0 3
1.0 0 0
pio 4 0 i 0.0 2 0 2 0 3
0.7 0 2
lio 3 0 i 0.0 2 0 2 0 3
0.7 0 2

I used cooked device.

If you use COOKED device or filesystem files for chunks you will only get
KAIO enabled if you include the following ONCONFIG parameter:

DIRECT_IO 1

Also, for best performance on AIX though you should set:

DIRECT_IO 2

Instead so that IDS also enables the AIX CONCURRENT IO feature.

Art

Art S. Kagel
Advanced DataTools (www.advancedatatools.com)
IIUG Board of Directors (art (AT) iiug (DOT) org)

See you at the 2010 IIUG Informix Conference
April 25-28, 2010
Overland Park (Kansas City), KS
www.iiug.org/conf

Disclaimer: Please keep in mind that my own opinions are my own opinions and
do not reflect on my employer, Advanced DataTools, the IIUG, nor any other
organization with which I am associated either explicitly, implicitly, or by
inference. Neither do those opinions reflect those of other individuals
affiliated with any entity with which I am affiliated nor those of the
entities themselves.



On Mon, Mar 1, 2010 at 4:21 AM, joe <joeclhua (AT) gmail (DOT) com> wrote:

joe wrote:
This is a bit confusing. You are using AIO, but for that you don't need
to to anything. You may want to use KAIO, and for that, when using
cooked files you'll need to set DIRECT_IO to 1 or 2. 1 will use direct
i/o and 2 will also use concurrent I/O (latest version on AIX only if I
recall correctly).

Regards.

Fernando Nunes wrote:
Ups... I should have read this more carefully. I checked the release
notes and the URL already provided. So everything is working, and the
release notes don't take 6.1 in consideration. Now You may still want to
use DIRECT_IO. Please check the manual.
Regards.