Re: [ADMIN] Raw devices vs. Filesystems - Mailing list pgsql-performance

From Grega Bremec
Subject Re: [ADMIN] Raw devices vs. Filesystems
Date
Msg-id 20040408043304.GA28539@elbereth.noviforum.si
Whole thread Raw
In response to Re: [ADMIN] Raw devices vs. Filesystems  (Josh Berkus <josh@agliodbs.com>)
Responses Re: [ADMIN] Raw devices vs. Filesystems
List pgsql-performance
...and on Wed, Apr 07, 2004 at 09:09:16AM -0700, Josh Berkus used the keyboard:
>
> Does it work, though?   Without Oracle admin tools?

Hello, Josh. :)

Well, as I said, that's why I was asking - I'm willing to give it a go
if nobody can prove me wrong. :)

> > Now, if both goals can be achieved in one go, hell, I'm willing to try
> > it out myself in an attempt to extract off of it, some performance
> > indicators that could be compared to other database performance tests
> > sent to both this and the PERFORM mailing list.
>
> Hey, any test you wanna run is fine with us.    I'm pretty sure that OCFS
> belongs to Oracle, though, patent & copyright, so we couldn't actually use it
> in practice.

I thought you knew - OCFS, OCFS-Tools and OCFSv2 have not only been open-
source for quite a while now - they're released under the GPL.

    http://oss.oracle.com/projects/ocfs/
    http://oss.oracle.com/projects/ocfs-tools/
    http://oss.oracle.com/projects/ocfs2/

I don't know what that means to you (probably nothing good, as PostgreSQL
is released under the BSD license), but it most definitely can be considered
a good thing for the end user, as she can download it, compile, and set it
up on her disks, without the need to pay Oracle royalties. :)

> If your intention in this test is to show the superiority of raw devices, let
> me give you a reality check: barring some major corporate backing getting
> involved, we can't possibly implement our own PG-FS for database support.  We
> already have a TODO list which is far too long for our developer pool, and
> implementing a custom FS either takes a large team (OCFS) or several years of
> development (Reiser).

Not really - I was just thinking about something not-entirely-a-filesystem
and POK!, OCFS sprang to mind. It omits many POSIX features that slow down
a traditional filesystem, yet it does know the concept of inodes and most
of all, it's _really_ heavy on caching. As such, it sounded quite promising
to me, but trial, I think, is the best test.

The question does spring up though, that Steve raised in another post - just
for the record, what POSIX semantics can a postmaster live without in a
filesystem?

Cheers,
--
    Grega Bremec
    Senior Administrator
    Noviforum Ltd., Software & Media
    http://www.noviforum.si/

Attachment

pgsql-performance by date:

Previous
From: Bruce Momjian
Date:
Subject: Re: good pc but bad performance,why?
Next
From: "Priem, Alexander"
Date:
Subject: data=writeback