trestusler_at_hotmail.com (Max) wrote in message news:<5a4548ca.0307061454.8ea7291_at_posting.google.com>...
> Sybrand Bakker <gooiditweg_at_sybrandb.demon.nl> wrote in message news:<ikfggvofqif50ci4p5kggkbrqfo887dbom_at_4ax.com>...
> > On 6 Jul 2003 04:56:53 -0700, trestusler_at_hotmail.com (Max) wrote:
> >
> > >WHy is an index creation taking more time with directio ?
> >
> > You are posting insufficient information.
> > forcedirectio applies to ufs filesystems only.
> Thanks for the reply.
> Sorry, it is UFS. didnt mention this because ufs is the default.
>
> > disk_async_io = true.
> isnt this the default ? Anyway a show parameters shows this to be
> true.
>
> > directio a truss will show you your lwp.kaio requests fail and Oracle
> > is reverting to normal buffered io.
>
> This seems to be what is happening. truss reports
>
> kaio(AIOWAIT, 0xFFFFFFFFFFFFFFFF) Err#22 EINVAL
>
>
> Reading some more newsgroup postings and articles from Sun it seems
> kaio is currently only available on raw and QIO with Veritas
> filesystems...
>
> Guess I'll need to do a lot more reading but hopefully someone here
> can give a quick answer.
>
> Is there any performance benefit to having a plain ufs filesystem
> mounted forcedirectio on solaris for oracle?
>
As you have already seen there isn't. Set disk_async_io to false and
you should see a performance benefit.
Sybrand Bakker
Senior Oracle DBA
Received on Mon Jul 07 2003 - 02:31:42 CDT
