From: Brad Nicholson <bnichols@ca.afilias.info>
To: Justin Pitts <justinpitts@gmail.com>
Cc: Devrim GÜNDÜZ <devrim@gunduz.org>
Cc: Ben Chobot <bench@silentmedia.com>
Cc: PostgreSQL - Performance <pgsql-performance@postgresql.org>
Subject: Re: Testing FusionIO
Date: Wed, 17 Mar 2010 10:41:31 -0400
Message-ID: <1268836891.4412.1782.camel@bnicholson-desktop> (raw)
In-Reply-To: <82964EE9-2507-4DB0-83A9-30DCCBBAE274@gmail.com>
References: <1268059301.2098.87.camel@hp-laptop2.gunduz.org>
<0A41C50D-3F29-4021-A959-95AF955D570F@silentmedia.com>
<1268829058.2137.31.camel@hp-laptop2.gunduz.org>
<1268831008.4412.1736.camel@bnicholson-desktop>
<86675EB2-8CC8-4159-91DD-27BB5E6AC1C3@gmail.com>
<1268831900.4412.1739.camel@bnicholson-desktop>
<82964EE9-2507-4DB0-83A9-30DCCBBAE274@gmail.com>
On Wed, 2010-03-17 at 09:52 -0400, Justin Pitts wrote:
> FusionIO is publicly claiming 24 years @ 5TB/day on the 80GB SLC device, which wear levels across 100GB of actual installed capacity.
> http://community.fusionio.com/forums/p/34/258.aspx#258
>
20% of overall capacity free for levelling doesn't strike me as a lot.
Some of the Enterprise grade stuff we are looking into (like TMS RamSan)
leaves 40% (with much larger overall capacity).
Also, running that drive at 80GB is the "Maximum Capacity" mode, which
decreases the write performance.
> Max drive performance would be about 41TB/day, which coincidently works out very close to the 3 year warranty they have on the devices.
>
To counter that:
http://www.tomshardware.com/reviews/fusioinio-iodrive-flash,2140-2.html
"Fusion-io’s wear leveling algorithm is based on a cycle of 5 TB
write/erase volume per day, resulting in 24 years run time for the 80 GB
model, 48 years for the 160 GB version and 16 years for the MLC-based
320 GB type. However, since 5 TB could be written or erased rather
quickly given the performance level, we recommend not relying on these
approximations too much."
> FusionIO's claim _seems_ credible. I'd love to see some evidence to the contrary.
Vendor claims always seem credible. The key is to separate the
marketing hype from the actual details.
Again, I'm just passing along what I heard - which was from a
vendor-neutral, major storage consulting firm that decided to stop
recommending these drives to clients. Make of that what you will.
As an aside, some folks in our Systems Engineering department here did
do some testing of FusionIO, and they found that the helper daemons were
inefficient and placed a fair amount of load on the server. That might
be something to watch of for for those that are testing them.
>
> On Mar 17, 2010, at 9:18 AM, Brad Nicholson wrote:
>
> > On Wed, 2010-03-17 at 09:11 -0400, Justin Pitts wrote:
> >> On Mar 17, 2010, at 9:03 AM, Brad Nicholson wrote:
> >>
> >>> I've been hearing bad things from some folks about the quality of the
> >>> FusionIO drives from a durability standpoint.
> >>
> >> Can you be more specific about that? Durability over what time frame? How many devices in the sample set? How did FusionIO deal with the issue?
> >
> > I didn't get any specifics - as we are looking at other products. It
> > did center around how FusionIO did wear-leveling though.
> > --
> > Brad Nicholson 416-673-4106
> > Database Administrator, Afilias Canada Corp.
> >
> >
>
--
Brad Nicholson 416-673-4106
Database Administrator, Afilias Canada Corp.
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To: pgsql-performance@postgresql.org
Cc: bnichols@ca.afilias.info, justinpitts@gmail.com, devrim@gunduz.org, bench@silentmedia.com
Subject: Re: Testing FusionIO
In-Reply-To: <1268836891.4412.1782.camel@bnicholson-desktop>
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