Thanks for all of your thoughts so far.... I am aware of the async I/O
requirements for Oracle, but never played with direct I/O. I will do some
testing with this and see what I can find out, and post some any findings
here for your reference.

Cheers

Andy Wilcox
Midrange Services
Aquila Networks Services Ltd

> -----Original Message-----
> From: PINNI, BALANAND (SBCSI) [SMTP:bp3965 AT SBC DOT COM]
> Sent: 23 April 2003 18:54
> To:   ADSM-L AT VM.MARIST DOT EDU
> Subject:      Re: AIX and async I/O
>
> I will post u the document with Oracle async IO set to false. What I am
> talking is Solaris has a option in /etc/vfstab for directio setting not
> for
> AIX.
>
> Here a comparison was only given .Yes the setting which was shown is for
> AIX
> TSM ,but what I said was for solaris os  tuneing that might work in the
> same
> way as this TSM setting for AIX.
>
> Once again Oracle aysnc io has two parameters .One is for disk and  the
> other is for tape drive . i.e disk aysnc io parameter that is set in
> init.ora parameter file was set to false.
>
>
> Hope this clears ur doughts.
>
>
>
> Thanks
> Balanand
>
>
> -----Original Message-----
> From: Zlatko Krastev/ACIT [mailto:acit AT ATTGLOBAL DOT NET]
> Sent: Wednesday, April 23, 2003 12:03 PM
> To: ADSM-L AT VM.MARIST DOT EDU
> Subject: Re: AIX and async I/O
>
> Unfortunately very misleading answer. I am also neither "down" nor "up" it
> but have done it.
> Do not mess disk settings with AIX Asynchronous I/O kernel extension.
> Oracle CANNOT work without AIX aio0 "Available" (look in *any* Oracle
> server Installation Guide).
> Second - it is AIXDIRECTIO not SOLARISDIRECTIO, isn't it.
> Both options have relevance to all types of volumes managed by TSM's LVM -
> DB, Log and diskpool (do not mess it with AIX LVM).
>
> Andy,
>
> I've installed v5.1.x servers with both options enabled but have not
> compared specifically improvement percentage. Some performance increase
> was visible. Was the increase due to these settings or just because code
> improvement since v4.2.x unfortunately I cannot state. What is obvious was
> memory consuption for AIX file caching which ought to come from Direct I/O
> option.
>
> Zlatko Krastev
> IT Consultant
>
>
>
>
>
>
> "PINNI, BALANAND (SBCSI)" <bp3965 AT SBC DOT COM>
> Sent by: "ADSM: Dist Stor Manager" <ADSM-L AT VM.MARIST DOT EDU>
> 23.04.2003 18:40
> Please respond to "ADSM: Dist Stor Manager"
>
>
>         To:     ADSM-L AT VM.MARIST DOT EDU
>         cc:
>         Subject:        Re: AIX and async I/O
>
>
> Andy,
>
> I have not down this tweaking. But I did do it in Oracle asyncio is set to
> false for SSA disks, since there were performance issues.
>
> When we used SSA disks for oracle we had very bad performance for commits.
> It took very long time to commit data in tables. But when we disabled it
> was
> over in few minutes.
>
> Second AIXDIRECTIO .....What I am guessing is that in SUN UNIX we have
> this
> parameter setting for /etc/vfstab mount options. Where instead of going
> through disk buffers the disk data is directly written on to disk for
> block
> special devices. This was already verified by someone on the list already.
>
> Hope the same applies to TSM TOO!!!
>
> I am just talking about only that I know about these parameters in their
> respective fields.
> I am very eager to know if someone has done in TSM too!!!
>
> I think one has relevance to DB volumes and the other with disk!!!!
>
> Balanand Pinni
>
> -----Original Message-----
> From: Wilcox, Andy [mailto:andy.wilcox AT AQUILA-NETWORKS.CO DOT UK]
> Sent: Wednesday, April 23, 2003 10:07 AM
> To: ADSM-L AT VM.MARIST DOT EDU
> Subject: AIX and async I/O
>
> Hiya,
>
> I have just been browsing through the latest admin guide for TSM, and have
> noticed new performance tuning tweaks on AIX. The two in quesiton are
> AIXASYNCIO and AIXDIRECTIO. Has anyone taken a look at enabling
> either/both
> of these options and found any worthwhile improvements at all?
>
> Cheers
>
> Andy Wilcox
> Midrange Services
> Aquila Networks Services Ltd
>
>
>
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