Re: 30 instances on one host

"Joel Garry" <joel-garry_at_nospam.cox.net> wrote in message news:slrnah2ro0.ho.joel-garry_at_zr1.vista1.sdca.cox.net...
> On Tue, 18 Jun 2002 04:01:17 GMT, Sean M <smckeown_at_earthlink.net> wrote:
> >Alan wrote:
> >>
> >> For example, OFA asks the DBA to place software on a mount point
> >> separate from the data mount points. The faulty logic behind this is
> >> that it will separate I/O and thus boost performance. The truth is
> >> that the software mount point will generate relatively little I/O; the
> >> software mount point would be quiet and the data mount points would be
> >> busy. So, a DBA following this advice would not optimize the I/O
> >> potential of the host.
> >>
> >> The OFA advice on mount points also holds little water when viewed
> >> from the perspective that on most decent sized UNIX boxes, I/O
> >> spreading is now done inside the storage array. The days of having a
> >> mount point logically connected to a disk partition's address are
> >> gone. OFA was written for systems built before the proliferation of
> >> disk volume management software like Veritas.
> >
> >This is not accurate. OFA is designed to address managability of Oracle
> >isntallations by providing guidelines for naming conventions and the
> >like. It is not designed to address performance. The reason to
> >separate Oracle software is not for performance, but for managability.
>
> It was indeed explicitly about performance, when the idea was to split
> I/O among physical disk devices. Eventually the reasons were watered down
> as it became cookbooked to /u001.../unnn, and completely stupid as modern
> storage hardware became prevalent. I just grabbed the old 7.0 Ault book
p. 12,
> summarizing 2 of the 3 rules of the OFA process have performance
implications;
> includes separating groups of segments that will contend for disk
resources
> (e. g. data and indexes);

Well, as we've seen on this newsgroup, this doesn't stand up, and Ault doesn't/didn't know what he was talking about. If he'd said tables and rollback segments, fair enough.

HJR
>and controlfile, redo log/group, and data that
> would have contention.
>
> >
> >> One bad naming convention in OFA is this:
> >>
> >> If you install an OFA-compliant Oracle Server, the Oracle home
> >> directory is
> >> $ORACLE_BASE/product/release_number.
> >>
> >> The above convention restricts the DBA from running 2 instances (or
> >> 30!) of the same release on one host.
> >
> >Only if you assume each instance must have its own code tree. But you
> >can certainly run more than one instance per code tree.
> >
> >That said, the reasons for running so many Oracle instances on the same
> >host are few and far between. I can only think of one organization in
> >our company that can justify such a configuration: training, where each
> >member of the class needs his or her own database for the exercises.
>
> I can additionally imagine a large org having a huge machine with a bunch
> of different depts with their own instances, for various reasonable
reasons.
> (Not to mention unreasonable reasons, but I won't go there). I agree that
> it would be pretty rare. Although, doesn't IBM run machines with
thousands
> of individual linux (linices?)...
>
> jg
> --
> These opinions are my own.
> http://www.garry.to Oracle and unix
guy.
> mailto:joel-garry_at_nospam.cox.net Remove nospam to
reply. Received on Thu Jun 20 2002 - 02:45:13 CDT