I am hoping someone here will help me. Was reading this site...
https://raid.wiki.kernel.org/index.php/Linux_Raid
and it said to email this list if you've tried everything other than
mdadm --create.
I am running Ubuntu 16.04. Machine name is fred. I used webmin to create
a 4 disk RAID10 array yesterday. I moved all my data onto the array.
Today, I had to reboot my PC. The resync was still not done, but I read
online that it's OK to boot during resync. After boot, my array was
gone. I checked syslog, and it just has this line:
DeviceDisappeared event detected on md device /dev/md0
I did not partition my disks before building the array. So I believe the
array consisted of /dev/sdc, /dev/sdd, /dev/sde, and /dev/sdf.
Here's some info...
stephen@fred> lsblk
NAME MAJ:MIN RM SIZE RO TYPE MOUNTPOINT
sda 8:0 0 117.4G 0 disk
├─sda1 8:1 0 109.7G 0 part /
├─sda2 8:2 0 1K 0 part
└─sda5 8:5 0 7.7G 0 part [SWAP]
sdb 8:16 0 465.8G 0 disk
└─sdb1 8:17 0 465.8G 0 part
sdc 8:32 0 3.7T 0 disk
sdd 8:48 0 3.7T 0 disk
sde 8:64 0 3.7T 0 disk
sdf 8:80 0 3.7T 0 disk
stephen@fred> sudo mdadm --examine /dev/sdc
[sudo] password for stephen:
/dev/sdc:
MBR Magic : aa55
Partition[0] : 4294967295 sectors at 1 (type ee)
stephen@fred>
stephen@fred> sudo mdadm --examine /dev/sdc1
mdadm: cannot open /dev/sdc1: No such file or directory
stephen@fred>
stephen@fred> sudo mdadm --examine /dev/sdd
/dev/sdd:
MBR Magic : aa55
Partition[0] : 4294967295 sectors at 1 (type ee)
stephen@fred>
stephen@fred> sudo mdadm --examine /dev/sde
/dev/sde:
MBR Magic : aa55
Partition[0] : 4294967295 sectors at 1 (type ee)
stephen@fred>
stephen@fred> sudo mdadm --examine /dev/sdf
/dev/sdf:
MBR Magic : aa55
Partition[0] : 4294967295 sectors at 1 (type ee)
stephen@fred> sudo mdadm --assemble --force /dev/md0 /dev/sdc /dev/sdd
/dev/sde /dev/sdf
mdadm: Cannot assemble mbr metadata on /dev/sdc
mdadm: /dev/sdc has no superblock - assembly aborted
Thank you for any help you can provide.
