From mboxrd@z Thu Jan 1 00:00:00 1970 From: Christian Deufel Subject: Re: Reassembling Raid5 in degraded state Date: Tue, 14 Jan 2020 12:28:06 +0100 Message-ID: <13b11d17-a23a-3063-70cb-de63d9fa7d09@inview.de> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 8bit Return-path: Sender: linux-raid-owner@vger.kernel.org To: linux-raid , Wols Lists List-Id: linux-raid.ids Hey Wol > My plan now would be to run mdadm --assemble --force /dev/md3 with 3 > disk, to get the Raid going in a degraded state. >Yup, this would almost certainly work. I would recommend overlays and >running a fsck just to check it's all okay before actually doing it on >the actual disks. The event counts say to me that you'll probably lose >little to nothing. So as I was trying to reassemble my Raid it crashed again. But this time sdc vanished. I get the following output: [root@dirvish ~]# mdadm --stop /dev/md3 mdadm: stopped /dev/md3 [root@dirvish ~]# mdadm --assemble --force /dev/md3 /dev/sdc1 /dev/sdd1 /dev/sdf            1 mdadm: forcing event count in /dev/sdc1(2) from 5995154 upto 5995162 mdadm: clearing FAULTY flag for device 0 in /dev/md3 for /dev/sdc1 mdadm: failed to add /dev/sdc1 to /dev/md3: Invalid argument mdadm: /dev/md3 assembled from 2 drives - not enough to start the array. and when I checked with fdisk sdc wasn't there anymore. [root@dirvish ~]# fdisk -l Disk /dev/sda: 250.0 GB, 250059350016 bytes 255 heads, 63 sectors/track, 30401 cylinders Units = cylinders of 16065 * 512 = 8225280 bytes    Device Boot      Start         End      Blocks   Id  System /dev/sda1   *           1          13      104391   fd  Linux raid autodetect /dev/sda2              14         535     4192965   fd  Linux raid autodetect /dev/sda3             536       30401   239898645   fd  Linux raid autodetect Disk /dev/sdb: 250.0 GB, 250059350016 bytes 255 heads, 63 sectors/track, 30401 cylinders Units = cylinders of 16065 * 512 = 8225280 bytes    Device Boot      Start         End      Blocks   Id  System /dev/sdb1   *           1          13      104391   fd  Linux raid autodetect /dev/sdb2              14         535     4192965   fd  Linux raid autodetect /dev/sdb3             536       30401   239898645   fd  Linux raid autodetect Disk /dev/sdd: 2000.3 GB, 2000398934016 bytes 255 heads, 63 sectors/track, 243201 cylinders Units = cylinders of 16065 * 512 = 8225280 bytes    Device Boot      Start         End      Blocks   Id  System /dev/sdd1   *           1      243201  1953512001   fd  Linux raid autodetect Disk /dev/sde: 2000.3 GB, 2000398934016 bytes 255 heads, 63 sectors/track, 243201 cylinders Units = cylinders of 16065 * 512 = 8225280 bytes    Device Boot      Start         End      Blocks   Id  System /dev/sde1   *           1      243201  1953512001   fd  Linux raid autodetect Disk /dev/sdf: 2000.3 GB, 2000398934016 bytes 255 heads, 63 sectors/track, 243201 cylinders Units = cylinders of 16065 * 512 = 8225280 bytes    Device Boot      Start         End      Blocks   Id  System /dev/sdf1               1      243201  1953512001   83  Linux ... After a reboot of the system sdc was back again but vanished again after I retried the assembly. Would the assembly also work with my 4th HDD, sde1 although in the mdadm --eaxmine it is labeld as spare? Greetings Christian