From owner-freebsd-isp Mon Jun 14 22:21:52 1999 Delivered-To: freebsd-isp@freebsd.org Received: from folly.lemis.com (unknown [192.109.197.162]) by hub.freebsd.org (Postfix) with ESMTP id 12B0B150EC for ; Mon, 14 Jun 1999 22:21:48 -0700 (PDT) (envelope-from grog@folly.lemis.com) Received: (grog@localhost) by folly.lemis.com (8.9.3/8.6.12) id IAA00517; Sat, 12 Jun 1999 08:04:02 -0700 (PDT) Message-ID: <19990612080231.64973@folly.lemis.com> Date: Sat, 12 Jun 1999 08:02:31 -0700 From: Greg Lehey To: Joe McDonald , Chris Cook Cc: freebsd-isp@freebsd.org Subject: Re: redunancy without RAID References: <37562454.718D3319@tcworks.net> <37683170.81567132@127.0.0.1> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii X-Mailer: Mutt 0.89i In-Reply-To: <37683170.81567132@127.0.0.1>; from Joe McDonald on Fri, Jun 11, 1999 at 08:57:40AM -0700 WWW-Home-Page: http://www.lemis.com/~grog Organization: LEMIS, PO Box 460, Echunga SA 5153, Australia Phone: +61-8-8388-8286 Fax: +61-8-8388-8725 Mobile: +61-41-739-7062 Sender: owner-freebsd-isp@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.org On Friday, 11 June 1999 at 8:57:40 -0700, Joe McDonald wrote: > On Thu, 03 Jun 1999 01:44:36 -0500, Chris Cook wrote: > >> We have been running VINUM here at our ISP for quite some time >> now. It works great... we have our /usr and /var partitions setup on 2 >> different mirrored volumes. The overhead is low and access times are >> great. With VINUM, if one of the mirrored disks go out, the volume should >> not crash . As far as ccd goes, I have never used it, but I believe >> both ccd and VINUM will not mirror a boot partition (I know VINUM won't >> yet). The VINUM was difficult to install, only because I was trying to use >> the port that comes with FBSD 3.1. I don't understand this. Vinum is part of the base system in 3.X. >> If you go this route, I suggest downloading the lastest version and >> you shouldn't have problems. Hope this helps... It's certainly a good idea to get the latest version. A lot of changes went in until about mid-April. > Do you know the best way to test if the mirror really works if a drive goes > bad? Pull the power to the drive as it's running? Pull the scsi cable to the > drive as it's running? Will this cause physical damage to the drive? I try both pulling the power cable and pulling the SCSI cable. It's possible that you could confuse the system if you pull the data cable during a transfer, but it hasn't happened to me yet, and anyway, this is a test environment. The way Vinum handles these errors, there are really only two errors that count: 1. Drive goes away. CAM reports "invalidating pack", and Vinum takes the drive down and all associated subdisks into the "crashed" state. If the drive comes back before any writes are attempted, the drive goes into a "reborn" state if there are other plexes, or an "up" state if there are none. In "reborn", Vinum will write to the subdisk, but it won't read it if it can get the data elsewhere. 2. I/O error on a transfer. Vinum marks the subdisk "stale". In either case, what happens to the plexes is relatively complex. Normally they're marked "degraded". The volumes stay up as long as *anything* is accessible (since otherwise you'd get I/O errors when you tried to access them). Greg -- Finger grog@lemis.com for PGP public key 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