From mboxrd@z Thu Jan 1 00:00:00 1970 From: Phil Turmel Subject: Re: Raid 5 to 6 migration Date: Fri, 01 Feb 2013 13:22:50 -0500 Message-ID: <510C07FA.4090405@turmel.org> References: ,<510C0075.9010908@turmel.org> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: Sender: linux-raid-owner@vger.kernel.org To: "Dominique C." Cc: linux-raid@vger.kernel.org List-Id: linux-raid.ids Hi Dominique, [Top-posting repaired. Please don't] On 02/01/2013 01:19 PM, Dominique C. wrote: [trim /] >>> I was wondering what would be the best way to convert a 6 hdd raid 5 to >>> raid 6. Ideally without having to reformat everything and lose all the >>> data in the process. I have backups of the data but I don't look forward >>> reinstalling everything on that server. >> >> 1) Add a seventh drive to the system. >> >> You can do this on the run if you have hotplug-capable sata ports or sas >> ports. >> >> 2) Add that drive to the array w/ "mdadm --add" >> 3) Convert array to raid6 w/ "mdadm --grow --level=raid6" >> >> You can do 2 & 3 on the run. >> >> 4) Monitor /proc/mdstat to see when it finishes. > Hi Phil, > > Thanks for your answer, however I forgot to mention one thing: I used 6 hdd out of 6 possible. No possibility to expand at this stage.... > The data only uses part of the space available. > Any other ideas ? Shrinking is usually possible, but there are many more steps, depending on what is in the array. Please provide more detail. The output of "lsdrv"[1] might be a good start. Phil [1] http://github.com/pturmel/lsdrv