From mboxrd@z Thu Jan 1 00:00:00 1970 From: Dan Stromberg Subject: Re: More tales of horror from the linux (HW) raid crypt Date: Wed, 22 Jun 2005 13:54:22 -0700 Message-ID: <1119473663.22853.189.camel@seki.nac.uci.edu> References: <5d96567b05061804477325d743@mail.gmail.com> <200506201853.11768.hjm@tacgi.com> <42B9BCF6.1010206@h3c.com> Mime-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="=-pjOvTwezHULFGJaM79Um" Return-path: In-Reply-To: <42B9BCF6.1010206@h3c.com> Sender: linux-raid-owner@vger.kernel.org To: Mike Hardy Cc: Harry Mangalam , linux-raid@vger.kernel.org, strombrg@dcs.nac.uci.edu List-Id: linux-raid.ids --=-pjOvTwezHULFGJaM79Um Content-Type: text/plain Content-Transfer-Encoding: quoted-printable On Wed, 2005-06-22 at 12:33 -0700, Mike Hardy wrote: > I'm very interested in the relative SW raid / HW raid performance. I > have both in service (two raid 5 sets are actually the same size with > the same number of components) and see roughly the same as you mention. > One difference that I see is that HW raid should generate fewer > interrupts and lower bus traffic. In the early days of RAID, people always used to say that for speed, you had to get a hardware RAID controller instead of doing software RAID. However, I saw an interesting comment on a local linux user group mailing list recently. That comment was to the effect that hardware RAID controllers tend to have no where near the horsepower of a modern desktop CPU - so the claim was (I've not verified this!) that using software RAID would be much faster. I'm thinking that if you can do software RAID with a dedicated box that's doing nothing but RAID and a little network, then yes, that likely would be faster than some scaled-down hardware RAID controller - but it would also likely cost more, be less likely to have good hot swap, and so on. --=-pjOvTwezHULFGJaM79Um Content-Type: application/pgp-signature; name=signature.asc Content-Description: This is a digitally signed message part -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.1 (GNU/Linux) iD8DBQBCuc/+o0feVm00f/8RAi4xAKCPoZ3ZltqzJV6ntYOHCzNlSelQkgCeOjKa Wj/DTI+QrpMCZsA3lrwlF7k= =7MdO -----END PGP SIGNATURE----- --=-pjOvTwezHULFGJaM79Um--