Hi,

After the installation of patch set 10.2.0.5, we seem to be hitting
bug 9949948: "Linux: Process spin under ksfdrwat0 if OS Async IO not
configured high enough". And even after several hits it won't die.
According to MOS, the workarounds are:
1) increase aio-max-nr on the OS level
2) disable async_io on the database level

We are on Red Hat 4 and apparently it's not possible to increase aio-
max-nr on this operating system? It's now set to 65536. I'm not really
in favor of disabling async_io for performance reasons...

Anyone else having the same problem and how did you solve this?

Thanks,
Matthias Hoys

On Thu, 02 Sep 2010 01:19:14 -0700, mhoys wrote:

> We are on Red Hat 4 and apparently it's not possible to increase aio-
> max-nr on this operating system? It's now set to 65536.

Why wouldn't it be possible to increase aio-max-nr?

$>cd /proc/sys/fs
 ADPRD1@oracle14 oracle Last rc=0 /proc/sys/fs 
 $>cat aio-max-nr 
300000
 ADPRD1@oracle14 oracle Last rc=0 /proc/sys/fs 
 $>cat /etc/redhat-release
Red Hat Enterprise Linux AS release 4 (Nahant Update 2)
 ADPRD1@oracle14 oracle Last rc=0 /proc/sys/fs 


-- 
http://mgogala.byethost5.com

On Sep 2, 8:40=A0am, Mladen Gogala <gogala.mla...@gmail.com> wrote:
> On Thu, 02 Sep 2010 01:19:14 -0700, mhoys wrote:
> > We are on Red Hat 4 and apparently it's not possible to increase aio-
> > max-nr on this operating system? It's now set to 65536.
>
> Why wouldn't it be possible to increase aio-max-nr?
>
> $>cd /proc/sys/fs
> =A0ADPRD1@oracle14 oracle Last rc=3D0 /proc/sys/fs
> =A0$>cat aio-max-nr
> 300000
> =A0ADPRD1@oracle14 oracle Last rc=3D0 /proc/sys/fs
> =A0$>cat /etc/redhat-release
> Red Hat Enterprise Linux AS release 4 (Nahant Update 2)
> =A0ADPRD1@oracle14 oracle Last rc=3D0 /proc/sys/fs
>
> --http://mgogala.byethost5.com

Lots of places run RedHat and have async IO in use.  I would double
check all the kernal parameters against the Installation Guide
requirements.

HTH -- Mark D Powell --

On Sep 2, 2:40=A0pm, Mladen Gogala <gogala.mla...@gmail.com> wrote:
> On Thu, 02 Sep 2010 01:19:14 -0700, mhoys wrote:
> > We are on Red Hat 4 and apparently it's not possible to increase aio-
> > max-nr on this operating system? It's now set to 65536.
>
> Why wouldn't it be possible to increase aio-max-nr?
>
> $>cd /proc/sys/fs
> =A0ADPRD1@oracle14 oracle Last rc=3D0 /proc/sys/fs
> =A0$>cat aio-max-nr
> 300000
> =A0ADPRD1@oracle14 oracle Last rc=3D0 /proc/sys/fs
> =A0$>cat /etc/redhat-release
> Red Hat Enterprise Linux AS release 4 (Nahant Update 2)
> =A0ADPRD1@oracle14 oracle Last rc=3D0 /proc/sys/fs
>
> --http://mgogala.byethost5.com

You are right! It can be changed on Red Hat 4.
Guess I have been confusing AIO-MAX-NR with AIO-MAX-SIZE! Stupid me...

Matthias