From mboxrd@z Thu Jan 1 00:00:00 1970 From: Oliver Martin Subject: Creating a 3-disk RAID6 array Date: Thu, 17 May 2012 03:24:26 +0200 Message-ID: <4FB4534A.5070608@volatilevoid.net> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-15; format=flowed Content-Transfer-Encoding: 7bit Return-path: Sender: linux-raid-owner@vger.kernel.org To: linux-raid@vger.kernel.org List-Id: linux-raid.ids Hi, is there any specific reason why md refuses to create a RAID6 array with 3 disks? My (probably naive) understanding suggests it should be the same as a 3-disk RAID1, similar to a 2-disk RAID5. The reason I'm asking is that I currently have space on three disks for a new array, and would like to expand it when I add a fourth. I tried this scenario with a few loopback devices, but the only way to go from a 3-disk RAID1 to a 4-disk RAID6 seems to be via an intermediate 3-disk RAID5, requiring two reshapes. I'd like to avoid one of them, if at all possible. Regards, Oliver