From mboxrd@z Thu Jan 1 00:00:00 1970 From: Guoqing Jiang Subject: Re: Growing RAID10 with active XFS filesystem Date: Wed, 10 Jan 2018 09:57:49 +0800 Message-ID: <39ae6b22-2404-1675-d007-b59702089b02@suse.com> References: <4892a03d-018c-8281-13d3-4fcc7acd2bb8@gmail.com> <232deaaa-7306-a01b-567f-ca5c74dc6077@suse.com> <5A538B30.4080601@youngman.org.uk> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <5A538B30.4080601@youngman.org.uk> Content-Language: en-US Sender: linux-raid-owner@vger.kernel.org To: Wols Lists , mdraid.pkoch@dfgh.net, linux-raid@vger.kernel.org List-Id: linux-raid.ids On 01/08/2018 11:16 PM, Wols Lists wrote: > On 08/01/18 07:31, Guoqing Jiang wrote: >> >> On 01/06/2018 11:44 PM, mdraid.pkoch@dfgh.net wrote: >>> Dear MD-experts: >>> >>> I was under the impression that growing a RAID10 device could be done >>> with an active filesystem running on the device. >> It depends on whether the specific filesystem provides related tool or >> not, eg, >> resize2fs can serve ext fs: > Sorry Guoqing, but I think you've *completely* missed the point :-( Yes, I just want to point is it is more safer to umount fs first, then do the reshape. There is another deadlock issue which mentioned by BingJing, it happened during reshape stage while some I/O come from vfs layer, though it is not the same issue, >> https://raid.wiki.kernel.org/index.php/Growing#Extending_the_filesystem >> >> And you can use xfs_growfs for your purpose. > You extend the filesystem *after* you've grown the array. The act of > growing the array has caused the filesystem to crash. That should NOT > happen - the act of growing the array should be *invisible* to the > filesystem. > > In other words, one or more of the following three are true :- > 1) The OP has been caught by some random act of God > 2) There's a serious flaw in "mdadm --grow" > 3) There's a serious flaw in xfs IMHO, there could be potential issue inside raid10/5, so I choose 2. Anyway, I will try to simulate the scenario and see what will happen ... Thanks, Guoqing