From owner-freebsd-hardware Fri Mar 6 22:30:17 1998 Return-Path: Received: (from majordom@localhost) by hub.freebsd.org (8.8.8/8.8.8) id WAA02540 for freebsd-hardware-outgoing; Fri, 6 Mar 1998 22:30:17 -0800 (PST) (envelope-from owner-freebsd-hardware@FreeBSD.ORG) Received: from allegro.lemis.com (allegro.lemis.com [192.109.197.134]) by hub.freebsd.org (8.8.8/8.8.8) with ESMTP id WAA02480 for ; Fri, 6 Mar 1998 22:30:07 -0800 (PST) (envelope-from grog@lemis.com) Received: from freebie.lemis.com (freebie.lemis.com [192.109.197.137]) by allegro.lemis.com (8.8.7/8.8.5) with ESMTP id QAA16813; Sat, 7 Mar 1998 16:59:50 +1030 (CST) Received: (from grog@localhost) by freebie.lemis.com (8.8.8/8.8.7) id QAA19526; Sat, 7 Mar 1998 16:59:50 +1030 (CST) (envelope-from grog) Message-ID: <19980307165949.63405@freebie.lemis.com> Date: Sat, 7 Mar 1998 16:59:49 +1030 From: Greg Lehey To: shimon@simon-shapiro.org Cc: freebsd-hardware@FreeBSD.ORG, Omar Thameen , Tom Subject: Re: getting oriented with RAID References: <19980307163951.57653@freebie.lemis.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii X-Mailer: Mutt 0.89i In-Reply-To: ; from Simon Shapiro on Fri, Mar 06, 1998 at 10:30:01PM -0800 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-hardware@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.org On Fri, 6 March 1998 at 22:30:01 -0800, Simon Shapiro wrote: > > On 07-Mar-98 Greg Lehey wrote: >> On Tue, 3 March 1998 at 17:28:48 -0800, Tom wrote: >>> >>> On Tue, 3 Mar 1998, Omar Thameen wrote: >>> >>>> I really want to make sure I understand the implementation of RAID >>>> on freebsd, because it looks like a great thing to have on production >>>> servers. Sorry if this continues to be very basic. >>> >>> Sorry, there is no "implementation of RAID on freebsd". RAID is >>> handled >>> by the controller. FreeBSD just sees a big disk. >> >> You're just barely correct. I'm writing a software RAID 5 >> implementation. ccd is a RAID 0/1 implementation. > > Ccd knows how to do ``write-only'' RAID-{0,1}. To recover from a failure, > under CCD is less than automatic. Tell me about it. It's about as easy as reading in a backup. > Also, to put your boot device on ccd RAID is less than trivial. I haven't tried that. Until recently, I didn't know it was possible. It should be possible with vinum, but I haven't finalized the details yet. > Recovery and management tools are essential for most people. Don't expect me to praise ccd. As far as I can tell, it's broken. I originally wanted to upgrade it for the features I wanted to add, but there's almost nothing of the original code left. Vinum recovers from failures automatically, even now. It also does (or will soon do) a lot of other neat things. Greg To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hardware" in the body of the message