Re: the argument with OFA and RAID

On Fri, 8 Oct 1999 06:38:31 +0200, "Sybrand Bakker" <postmaster_at_sybrandb.demon.nl> wrote:

I'm totally agree with Sybrand. OFA is twofolded. At our site we work with 2..3 DBA for several projects on several servers. We use OFA as a standard (style guide ???) to simplify the administration task. Let's say DBA A sets up database A using OFA. After a few days he goes for holiday. DBA B is now responsible fpr database A. No problem, because DBA A uses the site standard. Learning curve is small...

So for us the mean reason using OFA is to simplify admin tasks. This is true for using any other standards too.

It will help you to in distribution of filesystems too. But in the real life, I found myself limited in physical disks all the time ...  

>IMO,
>The only thing that really counts is the distribution of I/O amongst
>PHYSICAL!!! disks, as shown by the results of the iostat command.
>You could have a perfect OFA configuration laid out on different
>filesystems! as recommended, all on a single physical disk and it would help
>you NOTHING.
>That is, your disk is overflooded with requests and it can't handle the
>number of requests and the disk I/O queue is permanently non-zero.
>20 physical disks referred to as 1 logical disk by the O/S would put you at
>the mercy of RAID to distribute the files amongst physical disks, and you
>wouldn't be able to influence it. I would probably end-up in a severe
>argument with your colleague.
>IMO, the goal of OFA is twofold:
>- to make your setup transparent, so you wouldn't end up with files of
>multiple instances in one single directory structure
>- to make a 'reasonable' distribution of files amongst filesystems, which
>for me refers to physical disks.
>
>Hth,
>
>--
>Sybrand Bakker, Oracle DBA
>
>

Silvio Seifert
Foehrer Strasse 34
65199 Wiesbaden
Germany Received on Tue Oct 12 1999 - 02:07:49 CDT