From owner-freebsd-isp Wed Jun 20 18:46:35 2001 Delivered-To: freebsd-isp@freebsd.org Received: from wantadilla.lemis.com (wantadilla.lemis.com [192.109.197.80]) by hub.freebsd.org (Postfix) with ESMTP id 8338337B407 for ; Wed, 20 Jun 2001 18:46:30 -0700 (PDT) (envelope-from grog@lemis.com) Received: by wantadilla.lemis.com (Postfix, from userid 1004) id 4650D6ACBC; Thu, 21 Jun 2001 11:16:27 +0930 (CST) Date: Thu, 21 Jun 2001 11:16:27 +0930 From: Greg Lehey To: "Forrest W. Christian" Cc: freebsd-isp@freebsd.org Subject: Re: RAID/vinum options (mail server) Message-ID: <20010621111627.I86129@wantadilla.lemis.com> References: Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.2.5i In-Reply-To: ; from forrestc@imach.com on Wed, Jun 20, 2001 at 12:15:23PM -0600 Organization: The FreeBSD Project Phone: +61-8-8388-8286 Fax: +61-8-8388-8725 Mobile: +61-418-838-708 WWW-Home-Page: http://www.FreeBSD.org/ X-PGP-Fingerprint: 6B 7B C3 8C 61 CD 54 AF 13 24 52 F8 6D A4 95 EF Sender: owner-freebsd-isp@FreeBSD.ORG Precedence: bulk List-ID: List-Archive: (Web Archive) List-Help: (List Instructions) List-Subscribe: List-Unsubscribe: X-Loop: FreeBSD.org On Wednesday, 20 June 2001 at 12:15:23 -0600, Forrest W. Christian wrote: > I'm needing to find a RAID solution for our mail server. > > This is primarily for data integrity. So the solution MUST be > robust. In the past I've had raid controllers which freaked at loosing a > disk and refused to work with the array. Needless to say I was pissed. > > I am not opposed to vinum. I would like to hear more about it's > restrictions specifically in regards to the boot partition (meaning can I > vinum a slice on the same disk as the root partition) and it's robustness > on disk failure. The docs for vinum aren't too specific on this, unless > someone knows of some docs I don't know about. You currently can't have the root partition on a Vinum volume. That's the only limitation; you can have anything else, including swap, on a Vinum partition. Setting it up is a little tricky: you first need to install normally, then redefine the partitions as Vinum volumes by creating a Vinum drive (a partition of type Vinum) which starts 265 sectors before the beginning of the first partition, then defining subdisks to match the position of the partitions relative to the start of the drive. Robustness is good. You can have a failure and continue *if* you're in a redundant configuration (RAID-1 or RAID-5). You can also change disks online if you have a hot-pluggable configuration. We've seen some data consistency problems in the RAID-5 code, mainly relating to kernel race conditions. I have fixed all known issues, and I haven't heard of any problems since, but I certainly feel more confident about RAID-1 or RAID-10, which hasn't had any consistency issues reported in nearly 2 years. RAID-1 will also give you much better write performance than RAID-5 (on any platform; this is a limitation of the technique, not Vinum). Greg -- See complete headers for address and phone numbers To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-isp" in the body of the message