Well, the old saying never touch a running system held me up doing more fun stuff in my free-time.

To save me, and possible other from the hassle to search for a solutionworkaround again, here is what I did:

Problem:

fsck on Ubuntu would not like my software RAID after it was working for weeks, but I never rebootet the hardware.

Errors:

• “mount: /dev/md/1 ist kein gültiges blockorientiertes Gerät” 
• “failed to open /dev/md1″
• fsck bad superblock
• various others

Solution(s):

• add the module md into /etc/modules to have it loaded on runtime [1]
• make sure udev always creates /dev/md1, by telling him in /lib/udev/devices [2] by issuing mknod /lib/udev/devices/md1 b 9 1 
• put the config into /etc/mdadm/mdadm.conf so that issuing mdadm -A -s started the RAID so that it shows in cat /proc/mdstat as running
• HACK! /etc/init.d/checkfs.sh [2] to contain two additional lines: mdadm -A -s und sleep 5