Disable 'asyncdsk' driver then crash boot vmunix -lq -vga on rx integrity

[BERTRAND_7]

Hello,

We have an Oracle database 10g (10.1.0.4) running on our rx4640 integrity server (HPUX 11i v2).

As we use filesystems (and not raw device) for Oracle datafile, we wanted to disable asynchronous io for Oracle. Oracle init parameter (disk_asynch_io=false) has no effect on HPUX.
Before any settings, a huge number of oracle '.trc' files was generated in
$ORACLE_HOME/rdbms/log directory which is very annoying since it is located on the root disk.
The message was 'Ioctl ASYNC_CONFIG error, errno=1'
After reading the Oracle recommendation, we set 'dba MLOCK RTSCHED RTPRIO'
in the /etc/privgroup file and run '/usr/sbin/setprivgrp -f /etc/privgroup'.
The error message was still the same as previously mentionned.

We open a service request on oracle metalink that tells us to disable the 'asyncdsk' driver.

I'm not an expert of what 'asyncdsk' driver is used for on HPUX, but after disabling the system crash at boot.
Manually, we reboot without the '-vga' option in the auto boot EFI file and the system starts.

Is there any HP white paper on how to disable asynchronous io and the impacts (we already had a look on a very good power point presentation 'Best practises for Oracle on HPUX') but it is not very clear for me if asyncdsk driver must be disabled when not using raw device.
Is it correct that async io must only be used for raw device ?
Where is the truth ?

Any suggestion is welcome.

Regards.

Bruno

[RAC_1]

What makes you think that the crash is on account of disabling the async driver? did you look at crash dump? shutdownlog and ts99 file?

If you want to disabled oracle async, you can just change the perms on /dev/async to something other tha oracle:dba. No need to disabled async driver.

[Jayasuntar]

Dear Bruno,

What type of FS your are using?..

However please check the fs_async option in the kernel parameter. This will control sync or async write on FS.

Regards

Jay