From: Dave Chinner <david@fromorbit.com>
To: Stefan Ring <stefanrin@gmail.com>
Cc: Linux fs XFS <xfs@oss.sgi.com>
Subject: Re: A little RAID experiment
Date: Thu, 11 Oct 2012 08:27:33 +1100 [thread overview]
Message-ID: <20121010212733.GW23644@dastard> (raw)
In-Reply-To: <CAAxjCEwYyzTLTJk7SU0t=1SnT-V=7VadtKd0v9qj0soXtJ8XTg@mail.gmail.com>
On Wed, Oct 10, 2012 at 04:57:47PM +0200, Stefan Ring wrote:
> Btw, one of our customers recently aquired new gear with HP SmartArray
> Gen8 controllers. Now they are something to get excited about! This is
> the kind of write performance I would expect from an expensive server
> product. Check this out (this is again my artificial benchmark as well
> as random write of 4K blocks):
>
> SmartArray P400, 6 300G disks (10k, SAS) RAID 6, 256M BBWC:
^^^^
.....
> SmartArray Gen8, 8 300G disks (15k, SAS) RAID 5, 2GB FBWC:
^^^^
That's the reason for the difference in performance...
> So yeah, the disks are a bit faster. But what does that matter when
> there is such a huge difference otherwise?
Just inidicates that the working set for your test is much more
resident in the controller cache - has nothing to do with the disk
speeds. Tun a larger set of files/workload and the results will end
up a lot closer to disk speed instead of cache speed...
Cheers,
Dave.
--
Dave Chinner
david@fromorbit.com
_______________________________________________
xfs mailing list
xfs@oss.sgi.com
http://oss.sgi.com/mailman/listinfo/xfs
next prev parent reply other threads:[~2012-10-10 21:26 UTC|newest]
Thread overview: 41+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-04-25 8:07 A little RAID experiment Stefan Ring
2012-04-25 14:17 ` Roger Willcocks
2012-04-25 16:23 ` Stefan Ring
2012-04-27 14:03 ` Stan Hoeppner
2012-04-26 8:53 ` Stefan Ring
2012-04-27 15:10 ` Stan Hoeppner
2012-04-27 15:28 ` Joe Landman
2012-04-28 4:42 ` Stan Hoeppner
2012-04-27 13:50 ` Stan Hoeppner
2012-05-01 10:46 ` Stefan Ring
2012-05-30 11:07 ` Stefan Ring
2012-05-31 1:30 ` Stan Hoeppner
2012-05-31 6:44 ` Stefan Ring
2012-07-16 19:57 ` Stefan Ring
2012-07-16 20:03 ` Stefan Ring
2012-07-16 20:05 ` Stefan Ring
2012-07-16 21:27 ` Stan Hoeppner
2012-07-16 21:58 ` Stefan Ring
2012-07-17 1:39 ` Stan Hoeppner
2012-07-17 5:26 ` Dave Chinner
2012-07-18 2:18 ` Stan Hoeppner
2012-07-18 6:44 ` Stefan Ring
2012-07-18 7:09 ` Stan Hoeppner
2012-07-18 7:22 ` Stefan Ring
2012-07-18 10:24 ` Stan Hoeppner
2012-07-18 12:32 ` Stefan Ring
2012-07-18 12:37 ` Stefan Ring
2012-07-19 3:08 ` Stan Hoeppner
2012-07-25 9:29 ` Stefan Ring
2012-07-25 10:00 ` Stan Hoeppner
2012-07-25 10:08 ` Stefan Ring
2012-07-25 11:00 ` Stan Hoeppner
2012-07-26 8:32 ` Dave Chinner
2012-09-11 16:37 ` Stefan Ring
2012-07-16 22:16 ` Stefan Ring
2012-10-10 14:57 ` Stefan Ring
2012-10-10 21:27 ` Dave Chinner [this message]
2012-10-10 22:01 ` Stefan Ring
2012-04-26 22:33 Richard Scobie
2012-04-27 21:30 ` Emmanuel Florac
2012-04-28 4:15 ` Richard Scobie
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20121010212733.GW23644@dastard \
--to=david@fromorbit.com \
--cc=stefanrin@gmail.com \
--cc=xfs@oss.sgi.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.