From owner-freebsd-questions@FreeBSD.ORG Sat Dec 1 17:29:16 2007 Return-Path: Delivered-To: freebsd-questions@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 3E47616A46E for ; Sat, 1 Dec 2007 17:29:16 +0000 (UTC) (envelope-from bahamasfranks@gmail.com) Received: from wa-out-1112.google.com (wa-out-1112.google.com [209.85.146.183]) by mx1.freebsd.org (Postfix) with ESMTP id 0EB9913C4D9 for ; Sat, 1 Dec 2007 17:29:16 +0000 (UTC) (envelope-from bahamasfranks@gmail.com) Received: by wa-out-1112.google.com with SMTP id k17so3885958waf for ; Sat, 01 Dec 2007 09:29:15 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:received:received:message-id:date:from:reply-to:sender:to:subject:mime-version:content-type:content-transfer-encoding:content-disposition:x-google-sender-auth; bh=Tn7xDpXvxnJMwb4OLs2yoPYqH7+OUb0S0N+IkYLKQR4=; b=Jth37TA3ydBvVTQaBmlJ9EJxFk8+A+tucZPO0VIuE+ypmIRUIbNdo2oz0bv8vj3jt0zuNi8C1ay+dKWCWlsu0FMp9rj9g5eJ5aCxOePYETy2ebAHB8eeTvtZZbAgWVdOfNWvtKzFXkd1F3hLVkJLD3RbwSkvt3kNxol2hdZlpUY= DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=received:message-id:date:from:reply-to:sender:to:subject:mime-version:content-type:content-transfer-encoding:content-disposition:x-google-sender-auth; b=ckdWXHUDk16ebh1RBufSF+euMFfEsQyWo9aE0l5474P9l3yRYu95Ii0S0LiU9kz8POudYgrm5xzzA/qCqXPvGNX4xzQ80MIQQirP10CwDDhuyQl/oBvzP5ED/CQuLjNXCehBhIj2c/thFQhv8McbFopkwEKkk3gBfn4AKJ/y7CQ= Received: by 10.142.84.3 with SMTP id h3mr76822wfb.1196530155743; Sat, 01 Dec 2007 09:29:15 -0800 (PST) Received: by 10.142.194.10 with HTTP; Sat, 1 Dec 2007 09:29:15 -0800 (PST) Message-ID: <539c60b90712010929m7fef7020v806eb3c1eb24d066@mail.gmail.com> Date: Sat, 1 Dec 2007 10:29:15 -0700 From: "Steve Franks" Sender: bahamasfranks@gmail.com To: "User Questions" MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Content-Disposition: inline X-Google-Sender-Auth: d40639a50933890c Subject: using dd to duplicate disks/partitions of slightly different sizes - works? X-BeenThere: freebsd-questions@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list Reply-To: stevefranks@ieee.org List-Id: User questions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sat, 01 Dec 2007 17:29:16 -0000 I've got two 160GB disks. Different manufacturers, so different # bytes. One is FreeBSD, the other blank. I'd like to backup my system for the fastest possible recovery after a crash - move the plug and power up. I have gmirrored before, but I just wanted to do a quick dd, since I don't want to abuse my cheapo powersupply (has 4 disks already on it). Two questions: (1) If I dd from the smaller to the larger, will it work? What happens to the extra, say 5MB of unused space - will my partition info be messed up? (2) If I dd from the larger to the smaller (df reports only 50% used anyway) is there a way to make sure there is no info in the 5MB at the end that will overflow the smaller, and again, will my partitions be ok? The other option is just to fdisk & label the other disk, then rsync everything to it. Is that the wiser choice? Thanks, Steve