IDS Forum

Re: Raw device with Suse Linux Enterpise 10 an....

Posted By: Andreas Breitfeld
Date: Thursday, 17 January 2008, at 5:24 a.m.

In Response To: Re: Raw device with Suse Linux Enterpise 10 an.... (Art S. Kagel (Oninit LLC))

On Wednesday 16 January 2008 21:56, Art S. Kagel (Oninit LLC) wrote:
> Alexey Sonkin wrote:
> > Art, Sven,
> >
> > IDS 10 uses O_DIRECT with block devices (not cooked files!!)
> > when KAIO is ON.
> >
> > IDS 11 can use O_DIRECT for both cooked files and block devices,
> > and the use of DIRECT IO is controlled by the $ONCONFIG parameter.
> >
> > >From my own experience, RAW devices on Linux much work better with
> > > IDS
> >
> > 11,
> > then DIRECT IO with block devices: from OS diagnostics I can
> > clearly see,
> > that in some situations (most probably, Informix disk sorts in temp
> > dbspace), Linux buffer cache size abruptly increases.
>
> Great! I always suspected that RAW is still better. The question is
> how much better and is it worth the effort. Now if we can just
> convince Linus to not drop RAW disk support in Linux based on that
FYI, Linus already removed the deprecated status of the raw driver, see
http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commit;h=abd4aa5a97ebc0efb9a7fbc98ef0bcf39266fadf

Andreas

> ...
>
> Art S. Kagel
> Oninit
>
> > -Alexey
> >
> > Kagel (Oninit LLC)
> >
> > Schuran, Sven wrote:
> >> Hi,
> >>
> >> the raw device module is depreceated with Kernel 2.6.16.
> >> Everyone is talking about O_DIRECT access.
> >>
> >> Question: IDS10 is setting O_DIRECT automatically when I am using
> >> an
> >
> > LVM2
> >
> >> Partition?
> >
> > Direct IO support is off by default. You have to set "DIRECT_IO 1"
> > in your ONCONFIG file to enable it.
> >
> > However, I'm not certain it's even available in IDS 10.00, IB that
> > the first release to support direct_io is IDS 11.10xC1. Anyway also
> > note,
> >
> > from the Administrator's Guide for IDS v 11.10:
> >> DIRECT_IO is not used for temporary dbspaces and can only be used
> >> for dbspace chunks whose file systems support direct I/O for the
> >> page
> >
> > size.
> >
> > Art S. Kagel
> > Oninit
> >
> >> Thanks Sven
> >>
> >> ----------------------------------------------
> >> Sven Schuran - Maske AG - IT Operations
>
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Messages In This Thread

• Raw device with Suse Linux Enterpise 10 and INform
  Schuran, Sven -- Wednesday, 16 January 2008, at 12:23 p.m.
  • Re: Raw device with Suse Linux Enterpise 10 and IN
    Art S. Kagel (Oninit LLC) -- Wednesday, 16 January 2008, at 12:52 p.m.
    • RE: Raw device with Suse Linux Enterpise 10 an....
      Alexey Sonkin -- Wednesday, 16 January 2008, at 3:38 p.m.
      • Re: Raw device with Suse Linux Enterpise 10 an....
        Art S. Kagel (Oninit LLC) -- Wednesday, 16 January 2008, at 3:56 p.m.
        • RE: Raw device with Suse Linux Enterpise 10 an....
          Schuran, Sven -- Thursday, 17 January 2008, at 2:39 a.m.
          • Re: Raw device with Suse Linux Enterpise 10 an....
            Art S. Kagel (Oninit LLC) -- Thursday, 17 January 2008, at 9:04 a.m.
            • RE: Raw device with Suse Linux Enterpise 10 an....
              Alexey Sonkin -- Thursday, 17 January 2008, at 3:50 p.m.
              • Re: RE: Raw device with Suse Linux Enterpise 10 an
                RICHARD SPITZ -- Tuesday, 5 February 2008, at 6:39 a.m.
                • Re: Raw device with Suse Linux Enterpise 10 an
                  Art S. Kagel (Oninit LLC) -- Tuesday, 5 February 2008, at 6:49 a.m.
                  • RE: Raw device with Suse Linux Enterpise 10 an
                    Robert Roussey(IT) -- Tuesday, 5 February 2008, at 10:21 a.m.
                • RE: RE: Raw device with Suse Linux Enterpise 10 an
                  Noel Murphy -- Tuesday, 5 February 2008, at 7:03 a.m.
                • RE: RE: Raw device with Suse Linux Enterpise 10 an
                  Alexey Sonkin -- Tuesday, 5 February 2008, at 12:08 p.m.
        • RE: Raw device with Suse Linux Enterpise 10 an....
          Schuran, Sven -- Thursday, 17 January 2008, at 2:41 a.m.
        • Re: Raw device with Suse Linux Enterpise 10 an....
          Andreas Breitfeld -- Thursday, 17 January 2008, at 5:24 a.m.
          • Re: Raw device with Suse Linux Enterpise 10 an....
            Art S. Kagel (Oninit LLC) -- Thursday, 17 January 2008, at 9:05 a.m.

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