From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from pigeon.gentoo.org ([208.92.234.80] helo=lists.gentoo.org) by finch.gentoo.org with esmtp (Exim 4.60) (envelope-from ) id 1NxWKd-0004ME-5y for garchives@archives.gentoo.org; Fri, 02 Apr 2010 02:09:59 +0000 Received: from pigeon.gentoo.org (localhost [127.0.0.1]) by pigeon.gentoo.org (Postfix) with SMTP id B7742E07E8; Fri, 2 Apr 2010 02:09:07 +0000 (UTC) Received: from mail-pz0-f174.google.com (mail-pz0-f174.google.com [209.85.222.174]) by pigeon.gentoo.org (Postfix) with ESMTP id 81D60E07E8 for ; Fri, 2 Apr 2010 02:09:07 +0000 (UTC) Received: by pzk4 with SMTP id 4so1748738pzk.9 for ; Thu, 01 Apr 2010 19:09:07 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:mime-version:received:in-reply-to:references :date:received:message-id:subject:from:to:content-type; bh=0Vs2vbsX2uqoTuKwtoYXUsZmznVkBXjDEueaw7/TdLo=; b=EdDpv9DLVm0njVQ5GCceNPFhgfJ5t3aE/DW0NNn0lvTMLyhze9EhJlAzL6ibQ2qWAQ f5XXPWRBk6lKGm5JxfMoybw7/b8rBr1RXv5MzW4zZ2DixisqGT4C3dEsReGUWM6NUl9v 7AEFZJS5exXuTCNJZBffqkEhy7GleJNO+7XjM= DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :content-type; b=Ldcxr/PvI5wSNJ/OJ0l675HZScWimSvtCUUUGu39dnfkgjH+oiZTjBMVpOzu9B+BLw FmZqp2gZKvFgsNER34PH5dCAkZcwBvzn2pnXshxir0ltco01NyHxtVKurukqIk1KX3Lz wfqsJv7nwTejRg/ytD0ff+yO+Zl6F0V07qUhQ= Precedence: bulk List-Post: List-Help: List-Unsubscribe: List-Subscribe: List-Id: Gentoo Linux mail X-BeenThere: gentoo-user@lists.gentoo.org Reply-to: gentoo-user@lists.gentoo.org MIME-Version: 1.0 Received: by 10.143.13.4 with HTTP; Thu, 1 Apr 2010 19:09:06 -0700 (PDT) In-Reply-To: <20100402014000.GD5637@syscon4.inet> References: <20100401224820.GA5637@syscon4.inet> <20100402014000.GD5637@syscon4.inet> Date: Thu, 1 Apr 2010 19:09:06 -0700 Received: by 10.142.152.37 with SMTP id z37mr637467wfd.84.1270174146800; Thu, 01 Apr 2010 19:09:06 -0700 (PDT) Message-ID: Subject: Re: [gentoo-user] Duplicate identical Hard Disk From: Mark Knecht To: gentoo-user@lists.gentoo.org Content-Type: text/plain; charset=UTF-8 X-Archives-Salt: 0ff0ad7e-8d0e-4e23-9863-b6eeb758f7bc X-Archives-Hash: 9997fa7e924826c747f859f5bd8cc165 On Thu, Apr 1, 2010 at 6:40 PM, Joseph wrote: > On 04/01/10 17:43, Mark Knecht wrote: >> >> On Thu, Apr 1, 2010 at 4:02 PM, Paul Hartman >> wrote: >>> >>> On Thu, Apr 1, 2010 at 5:48 PM, Joseph wrote: >>>> >>>> I have two identical HD in the box and want to duplicate sda to sdb; >>>> sdb is not even partitioned. >>>> I think I could do: >>>> dd if=/dev/sda of=/dev/sdb >>>> but I need to boot from CD isn't it? >>> >>> Yes, basically, boot from USB or CD and use ddrescue to clone it, then >>> edit your fstab and I think you should be good. >>> >>> RAID1 would help if a drive physically dies, but if you had any >>> filesystem corruption or anything you'd just have an identically >>> corrupt copy on the second disk. >> >> A big part of my struggles over the last few days has been with mdadm >> & RAID1. I'm learning that we don't want to send someone down that >> path unless he has the right sort of disks. I'm having to deal with >> returns and reordering due to this. >> >> People should be aware of what is really required to do RAID before >> they get started so they don't duplicate my trials. I wasn't and I'm >> paying for it. (Almost literally if I don't get the drives in the >> mail!) ;-) >> >> Cheers, >> Mark > > So what you are folks saying is to stay away from RAID-1, beside as Paul > mention if I get any corruption and/or configuration (due to ebuild) with > RAID I'll be screwed anyhow. > So my best option is bootable CD and: > dd if=/dev/sda of=/dev/sdb > > But I'm kind of confused as to how to edit the "sdb" second drive. > I know I'll have to edit at lest: grub.conf and fstab > But how? > > 1.) Both disk are bootable, (have a boot sector) if I disconnect first one > sda, I think the second one will be recognize automatically as "sda" isn't > it? > 2.) If configure second drive after copying as "sdb" will it still boot if > fist disk is disconnected? > -- > Joseph > > With only 2 disks I personally think you're on the right path. With 3 disks I'm personally planning on RAID1 using 3 copies. If you disconnect the first disk (current sda) then most likely the original second disk (old sdb) becomes the new first disk. (sda) In that case no edits are required. However if you make them both bootable then assuming your BIOS supports it you can tell it to boot from the second disk. If you want the second disk booting to use the second disk's copy of Gentoo then you need to edit things to use sdb, not sda. that's probably overly complicated for what you are trying to do. I say make the copy, then disconnect the first drive physically and give it a try. This all presumes that you comtinue down this path with by hand copies. My comment about RAID was that I am learning the hard (alas expensive) way that not all disks can actually do RAID, at least not Linux software RAID, and really be usable. Cheers, Mark