From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from cuda.sgi.com (cuda2.sgi.com [192.48.176.25]) by oss.sgi.com (8.14.3/8.14.3/SuSE Linux 0.8) with ESMTP id n6KBLgfa077352 for ; Mon, 20 Jul 2009 06:21:42 -0500 Received: from mailsrv1.zmi.at (localhost [127.0.0.1]) by cuda.sgi.com (Spam Firewall) with ESMTP id 09851371CFD for ; Mon, 20 Jul 2009 04:22:23 -0700 (PDT) Received: from mailsrv1.zmi.at (mailsrv1.zmi.at [212.69.162.198]) by cuda.sgi.com with ESMTP id Tk1QTmb3BIOmF0BW for ; Mon, 20 Jul 2009 04:22:23 -0700 (PDT) Received: from mailsrv2.i.zmi.at (h081217106033.dyn.cm.kabsi.at [81.217.106.33]) (using TLSv1 with cipher DHE-RSA-CAMELLIA256-SHA (256/256 bits)) (Client CN "mailsrv2.i.zmi.at", Issuer "power4u.zmi.at" (not verified)) by mailsrv1.zmi.at (Postfix) with ESMTP id 2DBF44DAF for ; Mon, 20 Jul 2009 13:22:55 +0200 (CEST) Received: from saturn.localnet (unknown [10.72.27.2]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client did not present a certificate) by mailsrv2.i.zmi.at (Postfix) with ESMTPSA id 907CC40017E for ; Mon, 20 Jul 2009 13:22:22 +0200 (CEST) From: Michael Monnerie Subject: Re: data switchs su,sw and sunit,swidth Date: Mon, 20 Jul 2009 13:22:21 +0200 References: <4A626EC5.3090100@tlinx.org> In-Reply-To: <4A626EC5.3090100@tlinx.org> MIME-Version: 1.0 Message-Id: <200907201322.22102@zmi.at> List-Id: XFS Filesystem from SGI List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: multipart/mixed; boundary="===============8260629242487193609==" Sender: xfs-bounces@oss.sgi.com Errors-To: xfs-bounces@oss.sgi.com To: xfs@oss.sgi.com --===============8260629242487193609== Content-Type: multipart/signed; boundary="nextPart2080549.len0J7tyI9"; protocol="application/pgp-signature"; micalg=pgp-sha1 Content-Transfer-Encoding: 7bit --nextPart2080549.len0J7tyI9 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Content-Disposition: inline On Sonntag 19 Juli 2009 Linda Walsh wrote: > Then, for RAID 1 (mirror) would 'sw'=3D=3D1? =A0Would setting the =A0su/sw > =A0value for a RAID 1 actually matter in any way? =A0Ie, technically -- > it would fill in numbers for OS book-keeping, but wouldn't change > anything in terms of performance or layout, vs. 'physically' -- where > it could change disk layout or performance? > > At RAID 0, I'd guess =A0sw=3D=3D2? Both RAID0 and RAID1 use sw=3D0. > In RAID 5, would it be =A0 sw =A0=3D=3D #Disks-1? =A0So even w/6 disks, it > still only uses 1 disk for parity and =A0sw =3D=3D 5? RAID5: sw =3D #Disks-1 ( so with 8 disks use 7) RAID6: sw =3D #Disks-2 ( so with 8 disks use 6) > I wonder what becomes a max-safe RAID 5 size? (or is the number of > parity disks a settable option with RAID 5?) RAID5 always only has 1 parity disk (well, technically it's not a=20 physical disk, but the parity is distributed over all disks in the=20 array). Don't know what you mean by "max-safe" size. The more disks you have,=20 the bigger the chance that a single disk breaks. Also, I tested with=20 Areca controllers, using more than 7 disks in a single RAID array=20 doesn't improve speed anymore. So I use RAID-6 for up to 8 disks, and=20 make it RAID-60 for up to 16 disks (with Areca controllers). mfg zmi =2D-=20 // Michael Monnerie, Ing.BSc ----- http://it-management.at // Tel: 0660 / 415 65 31 .network.your.ideas. // PGP Key: "curl -s http://zmi.at/zmi.asc | gpg --import" // Fingerprint: AC19 F9D5 36ED CD8A EF38 500E CE14 91F7 1C12 09B4 // Keyserver: wwwkeys.eu.pgp.net Key-ID: 1C1209B4 --nextPart2080549.len0J7tyI9 Content-Type: application/pgp-signature; name=signature.asc Content-Description: This is a digitally signed message part. -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.9 (GNU/Linux) iEYEABECAAYFAkpkU24ACgkQzhSR9xwSCbRBHQCdFEiFEEdfQy3ZZ7CfZnTdGF79 lWMAnjDSVCEHFxd3K0cSGqRLCne1H60n =jLpb -----END PGP SIGNATURE----- --nextPart2080549.len0J7tyI9-- --===============8260629242487193609== Content-Type: text/plain; charset="us-ascii" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Content-Disposition: inline _______________________________________________ xfs mailing list xfs@oss.sgi.com http://oss.sgi.com/mailman/listinfo/xfs --===============8260629242487193609==--