From owner-freebsd-fs Fri Feb 13 20:39:41 1998 Return-Path: Received: (from majordom@localhost) by hub.freebsd.org (8.8.8/8.8.8) id UAA25673 for freebsd-fs-outgoing; Fri, 13 Feb 1998 20:39:41 -0800 (PST) (envelope-from owner-freebsd-fs@FreeBSD.ORG) Received: from parkplace.cet.co.jp (parkplace.cet.co.jp [202.32.64.1]) by hub.freebsd.org (8.8.8/8.8.8) with ESMTP id UAA25657 for ; Fri, 13 Feb 1998 20:39:36 -0800 (PST) (envelope-from michaelh@cet.co.jp) Received: from localhost (michaelh@localhost) by parkplace.cet.co.jp (8.8.8/CET-v2.2) with SMTP id EAA12433; Sat, 14 Feb 1998 04:38:47 GMT Date: Sat, 14 Feb 1998 13:38:47 +0900 (JST) From: Michael Hancock To: Greg Lehey cc: freebsd-fs@FreeBSD.ORG Subject: Re: ccd and ftd In-Reply-To: <19980214120247.43100@freebie.lemis.com> Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-freebsd-fs@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.org On Sat, 14 Feb 1998, Greg Lehey wrote: > On Sat, 14 February 1998 at 10:19:49 +0900, Michael Hancock wrote: > > I'm looking for a fault tolerant solution. I know Greg is working on a > > ftd driver. > > > > In the meantime I noticed that ccd supports mirroring. I'd like to mirror > > two arrays of 3 to 4 disk each. How well does this work? > > Do you mean more than one mirror? I don't believe that works. > Certainly I can't see how it can from reading the code. The man pages says you can mirror any even number of disks. What I'd like to do is this: 2940 - disk1 - disk2 - disk3 - disk4 and mirror/duplex the whole array with another identical array. 2940 - disk5 - disk6 - disk7 - disk8 Interestingly, man ccdconfig talks about CCDF_MIRROR and an unimplemented flag CCDF_PARITY. Although, it looks like they have hooks for more fault-tolerant features in ccd I agree with your effort to make a separate fault-tolerant driver and keeping the ccd a light-weight, primarily for striping-only driver. Are you going to be able to share some code with it? Regards, Mike Hancock To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-fs" in the body of the message