From mboxrd@z Thu Jan 1 00:00:00 1970 From: Phil Turmel Subject: Re: growing a RAID-10 array with mdadm 3.3.1+ ? Date: Tue, 11 Oct 2016 16:26:49 -0400 Message-ID: References: <1476206815.989242.752665505.6525EE00@webmail.messagingengine.com> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <1476206815.989242.752665505.6525EE00@webmail.messagingengine.com> Sender: linux-raid-owner@vger.kernel.org To: moft@fmailbox.com, linux-raid@vger.kernel.org List-Id: linux-raid.ids On 10/11/2016 01:26 PM, moft@fmailbox.com wrote: > (1) The changelog refers to 'near' and 'offset' layouts, but doesn't mention 'far'. Historically "far" has not been reshapeable at all. I don't recall seeing a patch that implemented it. If you attempt it and it doesn't support it, mdadm will refuse without hurting your array. Same is true for other reasons to reject growing. mdadm gives an error before touching the array. You can get a definitive answer by setting up a set of small loop devices in an array that mimics your setup and attempting to grow that test array. There have been bugs with SElinux and systemd preventing the reshape task from forking properly from the command line tool. The array is then stuck at reshape position 0. Phil