From mboxrd@z Thu Jan 1 00:00:00 1970 From: "David Rees" Subject: Re: Expanding a RAID-5 in use from 3 disks to 6 disks Date: Thu, 5 Jul 2007 16:43:51 -0700 Message-ID: <72dbd3150707051643t145d4fa9q1191aba89e2a4321@mail.gmail.com> References: <11456058.post@talk.nabble.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <11456058.post@talk.nabble.com> Content-Disposition: inline Sender: linux-raid-owner@vger.kernel.org To: acostoya Cc: linux-raid@vger.kernel.org List-Id: linux-raid.ids On 7/5/07, acostoya wrote: > > I've being trying to set a 6 disk RAID-5 for a few days but it took only 3 > disks (the other 3 gave Device busy error); in the meantime, an old server > went out of order so I have to use the incomplete host and it is now online > with user files. > > The question is, is there a way to expand my RAID-5 from 3 disks to 6 disks > without losing data?. Yes, it's possible. A quick google of 'linux expand raid 5' turned up a bunch of hits, FYI. Since you already have the 3 disks added to the array as spares, all you should have to do is: mdadm --grow /dev/md0 --raid-devices=6 Watch /proc/mdstat for the expansion status. After it is complete, you need to expand your filesystem to utilize the new larger device. Keep in mind that most people recommend raid 6 for larger raid 5 arrays since the likelyhood of multiple device failures goes up significantly the more drives you have in your array. Unfortunately I don't think it is possible to convert a raid 5 array to raid 6. -Dave