From owner-freebsd-hackers Fri Nov 28 11:00:09 1997 Return-Path: Received: (from root@localhost) by hub.freebsd.org (8.8.7/8.8.7) id LAA01273 for hackers-outgoing; Fri, 28 Nov 1997 11:00:09 -0800 (PST) (envelope-from owner-freebsd-hackers) Received: from trojanhorse.ml.org (mdean.vip.best.com [206.86.94.101]) by hub.freebsd.org (8.8.7/8.8.7) with ESMTP id LAA01212 for ; Fri, 28 Nov 1997 11:00:01 -0800 (PST) (envelope-from jamil@trojanhorse.ml.org) Received: from localhost (jamil@localhost) by trojanhorse.ml.org (8.8.8/8.8.5) with SMTP id KAA00243 for ; Fri, 28 Nov 1997 10:59:45 -0800 (PST) Date: Fri, 28 Nov 1997 10:59:45 -0800 (PST) From: "Jamil J. Weatherbee" To: hackers@freebsd.org Subject: Drive Mirroring Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-freebsd-hackers@freebsd.org X-Loop: FreeBSD.org Precedence: bulk I have two exact duplicate drives and I want the second (sd1) to be an exact duplicate of the first. Unfortunately ccd doesn't work here because the drives aren't bootable, you cannot install on ccd drives from the cds etc. One way to accomplish this is to go to single-user, sync, and then dd if=/dev/sd0 of=/dev/sd1 bs=1024k. Unfortunately using this method on a running system probably will corrupt the hell out of the copied over filesystem. I've also tried using dump, but for these 4.3 giggers it takes about 2 hours every night to remake filesystems on the second drive and dump | restore to it. Can anyone think of a way I could maintain an entire mirrored system without ccd, perhaps some software that nightly looks at the changes on one drive and puts them over to the second without basically rewriting the whole thing.