I have been having problem with my failed disk RAID server.
The regular mdadm --assemble cmd does not work.
After trial&error, I am able to add all disks to the RAID using mdadm.
Howver, it is still inactive. How do I activate this RAID md0?
The result from cat /proc/mdstat
md0 : inactive sdf1 sde1 sdd1 sdc1 sdb1