From owner-aic7xxx Mon Mar 22 0: 2:57 1999 Delivered-To: aic7xxx@freebsd.org Received: from frogger.cisco.com (frogger.cisco.com [171.69.30.57]) by hub.freebsd.org (Postfix) with ESMTP id 5870D14CEC for ; Mon, 22 Mar 1999 00:02:55 -0800 (PST) (envelope-from bjames@cisco.com) Received: (bjames@localhost) by frogger.cisco.com (8.8.5-Cisco.2-SunOS.5.5.1.sun4/8.6.5) id AAA09207; Mon, 22 Mar 1999 00:03:00 -0800 (PST) Date: Mon, 22 Mar 1999 00:03:00 -0800 (PST) From: Beau James Message-Id: <199903220803.AAA09207@frogger.cisco.com> To: AIC7xxx@FreeBSD.ORG, carlos@fisica.ufpr.br Subject: Re: SOFTWARE-RAID-TIPS (was: Adaptec 7890 and RAID portIII RAID controller Linux Support) Sender: owner-aic7xxx@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.org --> >Part of the reason for this is that if you had one big array, then all the --> >files on that array may be residing in the first portion of the disks. To --> >seek from any one file to another could be a relatively short seek. When --> >you split the filesystems, then a read of a file on each filesystem will --> >result in a half disk seek to get from one filesystem to another. --> >These half disk seeks will *destroy* your overall effective performance. --> --> OUCH!! This is VERY BAD news indeed :-( What you recommend is --> virtually impossible. If you have several partitions to put in the --> raid it'll cause an unacceptable loss of space... If you have to put --> /, /usr, /var and /home in the raid, how many disks will you need? Why bother breaking these directories into separate partitions, especially if you are going to put all of them onto a RAID array? Separate partitions is largely a historical artifact of *nix, based on the limited size of disks. What is the benefit of perpetuating it? Beau +-------------------------+---------------------+---------------------------+ + || || + Cisco Systems, Inc. + Beau James + + || || + 170 West Tasman Dr. + Mgr, xDSL Switch S/W + + |||| |||| + San Jose, CA 95134+ Phone: (408) 526-8328 + + ..:||||||:..:||||||:.. + + FAX: (408) 527-0495 + + Cisco Systems Inc. + + Email: bjames@cisco.com + +-------------------------+---------------------+---------------------------+ To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe aic7xxx" in the body of the message