From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from lists.gentoo.org ([140.105.134.102] helo=robin.gentoo.org) by nuthatch.gentoo.org with esmtp (Exim 4.43) id 1EAhfL-0001az-AH for garchives@archives.gentoo.org; Thu, 01 Sep 2005 05:31:11 +0000 Received: from robin.gentoo.org (localhost [127.0.0.1]) by robin.gentoo.org (8.13.4/8.13.4) with SMTP id j815RPcP028207; Thu, 1 Sep 2005 05:27:25 GMT Received: from fishbucket.homelinux.net (199-184-205-247-STUNET.ATU.EDU [199.184.205.247] (may be forged)) by robin.gentoo.org (8.13.4/8.13.4) with ESMTP id j815RL5H026084 for ; Thu, 1 Sep 2005 05:27:25 GMT Received: from athlon ([192.168.0.128]) by fishbucket.homelinux.net with esmtp (Exim 4.52) id 1EAhdx-0007nu-07 for gentoo-amd64@lists.gentoo.org; Thu, 01 Sep 2005 00:29:45 -0500 Subject: Re: [gentoo-amd64] Upgrading to Raid From: Kyle Liddell To: gentoo-amd64@lists.gentoo.org In-Reply-To: <20050901034637.38BC91B8BB@localhost.comcast.net> References: <20050901034637.38BC91B8BB@localhost.comcast.net> Content-Type: text/plain Date: Thu, 01 Sep 2005 00:29:44 -0500 Message-Id: <1125552584.9109.15.camel@athlon> Precedence: bulk List-Post: List-Help: List-Unsubscribe: List-Subscribe: List-Id: Gentoo Linux mail X-BeenThere: gentoo-amd64@gentoo.org Reply-to: gentoo-amd64@lists.gentoo.org Mime-Version: 1.0 X-Mailer: Evolution 2.2.3 Content-Transfer-Encoding: 7bit X-Archives-Salt: 902601d0-8acd-4586-ac99-61a7ff12ebb0 X-Archives-Hash: fa362ec4e059309ead0cf9164164e12f On Wed, 2005-08-31 at 21:46 -0600, scotthathcock@comcast.net wrote: > Is there a good Howto on migrating from a non Raid disk to Raid? I > recall seeing one but can't find it now. If you're really lazy (like me), you can convert your current running system over to RAID without messing with reinstalling from backups (although you probably should make the backups, hopefully you won't have to use them). Assuming you're doing RAID1, get your partitions and such set up on your new drive. Then set up the raid array (the howto on tldp.org is helpful, although be sure to use the newer mdadm setup even though the docs are a little thinner in the howto) on your new drive, marking the other drive in the array as bad/down. Copy say, /dev/hdxy to /dev/mdx, and then edit the proper config files so that when you reboot you'll be using the raid array. Once you're in it, change the other drive in the array from bad to the old drive, and it'll rebuild the array on the fly. It's pretty neat. (If you do that method though, read the docs very carefully to make sure you're doing it right. It's been a while since I've done it so I may have gotten something backwards or some such.) I wouldn't worry about any performance hits: A few months ago I converted an old P2 450mhz system to RAID 1+0 and noticed no performance hits, and even went to raid1 + lvm and again no problems. I've since added an additional CPU to that box, but hard drives are just so much slower than your CPU that it'd take a lot of work to create a slowdown. Also, if there's any chance you'll want to maybe resize your partitions, or especially, add more drives to the system, I would very strongly suggest looking into LVM (Linux Volume Manager). It plays well with raid (instead of raid1+0 I'm doing the equivalent with raid1+lvm, but no worries about adding more disks) and lets you alter "partitions" on the fly. If you want to add more storage, just buy a pair of drives, raid1 them, then just append it to the end of your volume, and run your favorite on the fly partition resizer and enjoy. By the way, a $15 promise ATA100 two channel IDE PCI card + a pair of $80 120gb seagate HDDs is quite a nice deal. I've got two of the Promise IDE cards in my server, and they seem to be pretty good PATA cards if you're into that sort of thing. Kyle -- gentoo-amd64@gentoo.org mailing list