From: Dave Cramer <pg@fastcrypt.com>
To: David Rees <drees76@gmail.com>
Cc: david@lang.hm
Cc: pgsql-performance@postgresql.org
Subject: Re: I have a fusion IO drive available for testing
Date: Tue, 31 Mar 2009 08:20:41 -0400
Message-ID: <491f66a50903310520j2d540fa9q3c0f8403bad60c14@mail.gmail.com> (raw)
In-Reply-To: <72dbd3150903271333pfd63105i8076bf26858eaee1@mail.gmail.com>
References: <491f66a50903260547p552f6d86kc51f8988898c19e4@mail.gmail.com>
<alpine.DEB.1.10.0903271026590.20251@asgard.lang.hm>
<72dbd3150903271333pfd63105i8076bf26858eaee1@mail.gmail.com>
On Fri, Mar 27, 2009 at 4:33 PM, David Rees <drees76@gmail.com> wrote:
> On Fri, Mar 27, 2009 at 10:30 AM, <david@lang.hm> wrote:
> > On Thu, 26 Mar 2009, Dave Cramer wrote:
> >> So far using dd I am seeing around 264MB/s on ext3, 335MB/s on ext2
> write
> >> speed. So the question becomes what is the best filesystem for this
> drive?
> >
> > until the current mess with ext3 and fsync gets resolved, i would say it
> > would probably be a bad choice. I consider ext4 too new, so I would say
> XFS
> > or ext2 (depending on if you need the journal or not)
>
> If you're worried about the performance implications of ext3 in
> data=ordered mode, the best thing to do is to mount the filesystem in
> data=writeback mode instead.
>
> If you're only using the filesystem for PostgreSQL data or logs, your
> data will be just as safe except now that data and metadata won't be
> forced to disk in the order it was written.
>
> And you still get the benefit of a journal so fsck's after a crash will be
> fast.
>
> XFS probably is a decent choice, but I don't have much experience with
> it except on a desktop system where I can tell you that having write
> barriers on absolutely kills performance of anything that does a lot
> of filesystem metadata updates. Again, not a big concern if the
> filesystem is only being used for PostgreSQL data or logs.
>
> -Dave
>
So I tried writing directly to the device, gets around 250MB/s, reads at
around 500MB/s
The client is using redhat so xfs is not an option.
Dave
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To: pgsql-performance@postgresql.org
Cc: pg@fastcrypt.com, drees76@gmail.com, david@lang.hm
Subject: Re: I have a fusion IO drive available for testing
In-Reply-To: <491f66a50903310520j2d540fa9q3c0f8403bad60c14@mail.gmail.com>
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