We're running a small server over here on a raspberry pi, debian jessie, to host both our owncloud and - more important - our repo and build server.
To be sure that data will not get corrupted, I have set up a software raid, spanning across two USB drives.
After trying to rename the machine, and obviously, after the first reboot after setting up the MD, I am not able to get it back up and running:
root@pi3:~# cat /proc/mdstat
Personalities :
unused devices: <none>
root@pi3:~# mdadm --examine --brief --scan
ARRAY /dev/md/0 metadata=1.2 UUID=125e3855:8c3326a2:dd067877:60d35ba7 name=pi3:0
root@pi3:~# ls /dev/md0
ls: cannot access /dev/md0: No such file or directory
root@pi3:~# fdisk -l | grep Linux
/dev/mmcblk0p2 137216 61962239 61825024 29.5G 83 Linux
/dev/sda1 2048 1953523711 1953521664 931.5G fd Linux raid autodetect
/dev/sdb1 2048 1953523711 1953521664 931.5G fd Linux raid autodetect
/dev/sdc2 41945088 312581807 270636720 129.1G 83 Linux
From what I understood so far, the mdadm should be able to provide the array - after all the devices are there and can be detected.
However, I cannot mount /dev/md0 anymore because there are no personalities detected.
Is there anybody who can point me to the next steps? Googling for an empty personalities line is not so successful and the personalities line does not contain a catchy keyword...