From owner-freebsd-stable Mon Sep 3 11:21: 5 2001 Delivered-To: freebsd-stable@freebsd.org Received: from topperwein.dyndns.org (acs-24-154-28-172.zoominternet.net [24.154.28.172]) by hub.freebsd.org (Postfix) with ESMTP id 93B2137B409 for ; Mon, 3 Sep 2001 11:21:00 -0700 (PDT) Received: from topperwein.dyndns.org (topperwein.dyndns.org [192.168.168.10]) by topperwein.dyndns.org (8.11.6/8.11.6) with ESMTP id f83IL1910973 for ; Mon, 3 Sep 2001 14:21:01 -0400 (EDT) (envelope-from behanna@zbzoom.net) Date: Mon, 3 Sep 2001 14:20:56 -0400 (EDT) From: Chris BeHanna Reply-To: Chris BeHanna Cc: FreeBSD-Stable Subject: Re: RAID5 In-Reply-To: <030201c1349b$a0c254b0$2aa8a8c0@melim.com.br> Message-ID: <20010903141721.D10812-100000@topperwein.dyndns.org> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-freebsd-stable@FreeBSD.ORG Precedence: bulk List-ID: List-Archive: (Web Archive) List-Help: (List Instructions) List-Subscribe: List-Unsubscribe: X-Loop: FreeBSD.ORG On Mon, 3 Sep 2001, Ronan Lucio wrote: > Hi All, > > I have a doubt about RAID5: > > If I have 3 HDs with 36 Gb each in RAID5, what is > my total abaliable space? 72GB. > Can I select it? > For example: Can I create 20 Gb for parity + 88 Gb of > avaliable space? No. RAID-5 stripes parity information across all three drives: data data parity data parity data parity data data etc. You can bump up the available space by adding more spindles (only one stripe of a stripeset is parity), but the tradeoff is that the parity calculations may degrade write performance when you do that. FWIW, I set up a 4-drive RAID-5 volume with an associated journaling device on Solaris 8 that performs pretty well for home directories. I wouldn't expect vinum to be any different in that regard, given sufficient CPU (my Solaris volume is served from a two-CPU E450, just as a reference point). -- Chris BeHanna Software Engineer (Remove "bogus" before responding.) behanna@bogus.zbzoom.net I was raised by a pack of wild corn dogs. To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-stable" in the body of the message