From owner-freebsd-scsi Thu Sep 26 19:38:01 1996 Return-Path: owner-freebsd-scsi Received: (from root@localhost) by freefall.freebsd.org (8.7.5/8.7.3) id TAA23537 for freebsd-scsi-outgoing; Thu, 26 Sep 1996 19:38:01 -0700 (PDT) Received: from silvia.HIP.Berkeley.EDU (ala-ca16-06.ix.netcom.com [204.32.168.134]) by freefall.freebsd.org (8.7.5/8.7.3) with ESMTP id TAA23372 for ; Thu, 26 Sep 1996 19:37:37 -0700 (PDT) Received: (from asami@localhost) by silvia.HIP.Berkeley.EDU (8.7.6/8.6.9) id TAA18470; Thu, 26 Sep 1996 19:36:32 -0700 (PDT) Date: Thu, 26 Sep 1996 19:36:32 -0700 (PDT) Message-Id: <199609270236.TAA18470@silvia.HIP.Berkeley.EDU> To: bsdscsi@shadows.aeon.net CC: freebsd-scsi@freebsd.org In-reply-to: <199609221053.NAA14141@shadows.aeon.net> (message from mika ruohotie on Sun, 22 Sep 1996 13:53:43 +0300 (EET DST)) Subject: Re: striping/mirroring? From: asami@freebsd.org (Satoshi Asami) Sender: owner-freebsd-scsi@freebsd.org X-Loop: FreeBSD.org Precedence: bulk * i've asked this one on usenet before too, but got no replies... * * i'm about to set up a server that's meant to be "serious" in some * sense... * * the machine will be ga586hx512 boarded, about 128 megs of ram (later more), * and i will get adaptec 3940uw... * * now, what i want to know is which scsi drives would give me the best * performance/reliability... i've personally thought using barracuda 4lp, * but i feel a bit sceptic it's reliability... What performance? Sequential or random? I'm assuming that ga586hx512 is an Intel 430 HX with 512KB of cache, that's as good as it gets as far as motherboards go. If you want to maximize sequential access, you'll need about 6 or 7 disks to stripe across them, you'll get to about 28 MB/s with the option "I586_FAST_BCOPY". For random access, you'll need more like 30 drives through the filesystem to max out the motherboard. * anyway, the plot is, if freebsd is able to do it (i know how to strip * disks, not how to mirror) that i'd use disk striping on 3-4 drives, and * would mirror it to one... can i? how, if i can? That isn't mirroring. ;) If you have 2N drives, mirroring will make that look like a N-disk ccd. Satoshi