From mboxrd@z Thu Jan 1 00:00:00 1970 From: David Brown Subject: Re: looking for advice on raid drives upgrade Date: Wed, 30 Mar 2011 15:14:55 +0200 Message-ID: References: Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: Sender: linux-raid-owner@vger.kernel.org To: linux-raid@vger.kernel.org List-Id: linux-raid.ids On 30/03/2011 11:46, Vincent Schut wrote: > Hi all, > > one of my raid's is currently a raid5 with 4 1TB drives, which I'm going > to upgrade by replacing all drives with 2TB drives. > Main question: what is recommended: > > - offline the raid, dd(rescue) each 1TB drive onto a new 2TB one, > replace drives, put raid online again > > or: > - manually replace one drive at a time, and let the raid recover and > thus write the data onto the new drive? > > As far as I know all current drives are healthy; regularly SMART > monitoring and raid checks have not ringed any bells sofar. > > I guess offlining and dd-ing would be more secure, but I might miss > something and would like to hear other considerations from people more > experienced in this area. > > Regards, > Vincent Schut. > If you've got a spare drive slot, and plenty of time, there is another option that lets you keep online and redundant during the process. Re-shape the array to raid 6, while adding one of the new drives. Then you can replace each drive, one at a time, letting the raid recover in between. For the last drive, you just have to remove it then reshape back to raid 5 (although ideally you could buy an extra drive and keep the raid 6 layout - it's worth the cost, assuming you have the drive slot). Once everything is swapped over, you grow the array to fit the new disks.