On 5/6/23 18:28, Alex Elder wrote:
I have a 3-drive RAID5 that I set up more than 5 years ago. At some point, the "middle" drive failed (hardware failure). I bought a replacement and issued some commands to attempt to recover, and did *something* wrong. I was too busy to spend time to fix this then, and one thing led to another, and now it's 2023 and I'd like to fire the array up again. The current state is that /dev/md127 gets created automatically and it contains the two good disks (partitions). I'm pretty sure this should be easy enough to recover if I issue the right commands to rebuild things. The disks are 8TB Seagate Ironwolf drives. (ST8000VN0022-2EL) They are partitioned identically, with a GPT label. The first partition starts at offset 2048 sectors and continues to the end. The RAID device was originally created with this command: mdadm --create /dev/md/z --level=5 --raid-devices=3 /dev/sd{b,c,d}1 I'm going to provide the output of a few commands below, and will gladly provide whatever other information is required to get this fixed. Thank you. -Alex root@meat:/# mdadm --version mdadm - v4.2 - 2021-12-30 - Ubuntu 4.2-3ubuntu1 root@meat:/# root@meat:/# mdadm --detail --scanINACTIVE-ARRAY /dev/md127 metadata=1.2 name=meat:z UUID=8a021a34:f19bbc01:7bcf6f8e:3bea43a9root@meat:/# root@meat:/# mdadm --detail /dev/md127 /dev/md127: Version : 1.2 Raid Level : raid5 Total Devices : 2 Persistence : Superblock is persistent State : inactive Working Devices : 2 Name : meat:z (local to host meat) UUID : 8a021a34:f19bbc01:7bcf6f8e:3bea43a9 Events : 9534 Number Major Minor RaidDevice - 8 49 - /dev/sdd1 - 8 17 - /dev/sdb1 root@meat:/# root@meat:/# ls -l /dev/sd[bcd]1 brw-rw---- 1 root disk 8, 17 May 6 11:20 /dev/sdb1 brw-rw---- 1 root disk 8, 33 May 6 11:20 /dev/sdc1 brw-rw---- 1 root disk 8, 49 May 6 11:20 /dev/sdd1 root@meat:/# =========== Here's the disk that got replaced root@meat:/# mdadm --examine /dev/sdc1 mdadm: No md superblock detected on /dev/sdc1. root@meat:/# =========== Here are the other two disks root@meat:/# mdadm --examine /dev/sd[bd]1 /dev/sdb1: Magic : a92b4efc Version : 1.2 Feature Map : 0x1 Array UUID : 8a021a34:f19bbc01:7bcf6f8e:3bea43a9 Name : meat:z (local to host meat) Creation Time : Sun Oct 22 21:19:23 2017 Raid Level : raid5 Raid Devices : 3 Avail Dev Size : 15627786240 sectors (7.28 TiB 8.00 TB) Array Size : 15627786240 KiB (14.55 TiB 16.00 TB) Data Offset : 262144 sectors Super Offset : 8 sectors Unused Space : before=262064 sectors, after=0 sectors State : clean Device UUID : 4cd855b7:ecba9064:b74a2182:bbc8a994 Internal Bitmap : 8 sectors from superblock Update Time : Sun Dec 13 16:51:21 2020 Bad Block Log : 512 entries available at offset 40 sectors Checksum : be977447 - correct Events : 9534 Layout : left-symmetric Chunk Size : 512K Device Role : Active device 0 Array State : AAA ('A' == active, '.' == missing, 'R' == replacing) /dev/sdd1: Magic : a92b4efc Version : 1.2 Feature Map : 0x1 Array UUID : 8a021a34:f19bbc01:7bcf6f8e:3bea43a9 Name : meat:z (local to host meat) Creation Time : Sun Oct 22 21:19:23 2017 Raid Level : raid5 Raid Devices : 3 Avail Dev Size : 15627786240 sectors (7.28 TiB 8.00 TB) Array Size : 15627786240 KiB (14.55 TiB 16.00 TB) Data Offset : 262144 sectors Super Offset : 8 sectors Unused Space : before=262064 sectors, after=0 sectors State : clean Device UUID : 1d2ce616:943d0c86:fa9ef8ad:87e31be0 Internal Bitmap : 8 sectors from superblock Update Time : Sun Dec 13 16:51:21 2020 Bad Block Log : 512 entries available at offset 40 sectors Checksum : b6ece242 - correct Events : 9534 Layout : left-symmetric Chunk Size : 512K Device Role : Active device 2 Array State : AAA ('A' == active, '.' == missing, 'R' == replacing) root@meat:/#
mdadm manage /dev/md127 --add /dev/sdd ? Cheers, Hannes -- Dr. Hannes Reinecke Kernel Storage Architect hare@xxxxxxx +49 911 74053 688 SUSE Software Solutions GmbH, Maxfeldstr. 5, 90409 Nürnberg HRB 36809 (AG Nürnberg), Geschäftsführer: Ivo Totev, Andrew Myers, Andrew McDonald, Martje Boudien Moerman
