From mboxrd@z Thu Jan 1 00:00:00 1970 From: Konstantin Svist Subject: [SOLVED] Re: messed up changing chunk size Date: Tue, 20 Jul 2010 09:30:26 -0700 Message-ID: <4C45CF22.4060900@gmail.com> References: <4C439D19.4070906@gmail.com> <4C44939A.1060200@gmail.com> <4C4525E8.2010702@relevad.com> <4C454246.3030703@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <4C454246.3030703@gmail.com> Sender: linux-raid-owner@vger.kernel.org To: linux-raid@vger.kernel.org List-Id: linux-raid.ids On 07/19/2010 11:29 PM, Konstantin Svist wrote: > On 07/19/2010 09:28 PM, Konstantin Svist wrote: >> Can someone confirm that this command should work to revert the size? >> mdadm --grow -z 879100608 >> --backup-file=/root/grow_md0_size_revert.bak /dev/md0 > > Finally sat down and thought about it - created a temporary raid using > /dev/ram## and copied some files to it, did the same operations on it. > Amazingly, all the files came back. Will see if the real thing works too For some reason, mdadm refused to resize back to max: # mdadm --grow -z max --backup-file=/root/grow_md0_size_back.bak /dev/md0 mdadm: component size of /dev/md0 has been set to 293033536K # cat /proc/mdstat Personalities : [raid6] [raid5] [raid4] md0 : active raid5 sdd1[3] sda4[0] sdc1[2] sdb1[1] 293033472 blocks level 5, 64k chunk, algorithm 2 [4/4] [UUUU] After stopping and re-assembling the array, though, it comes up with full size but with only 3 of 4 drives: # mdadm --assemble --scan mdadm: /dev/md0 has been started with 3 drives (out of 4). # cat /proc/mdstat Personalities : [raid6] [raid5] [raid4] md0 : active raid5 sda4[0] sdc1[2] sdb1[1] 879100608 blocks level 5, 64k chunk, algorithm 2 [4/3] [UUU_] The array is degraded but data is all there, so I'm backing it up right now. No idea why it doesn't like the 4th drive.