Thank you for answering!
quoted
After rebooting the system, one of the harddisks was missing from my md raid 6 (the drive was /dev/sdf), so i rebuilt it with a hotspare that was already present in the system.
I physically removed the "missing" /dev/sdf drive after the restore and replaced it with a new drive.
Exact commands involved for those steps?
Well since the /dev/sdf disk was missing from the array after the reboot, i didn't use any command to remove it. I just used
$ mdadm --run /dev/md0
to trigger the rebuild/restore. As i had two spare drives present in the array anyway, i thought that was the smartest thing to do.
After the restore was done, i shut down the system and swapped the missing disk (/dev/sdf) with a new one.
I then added the new disk to the array as a spare (mdadm --add /dev/md0 /dev/sdf)
mdadm --examine output for your disks?
Here is the output for every disk in the array: http://pastebin.com/JW8rbJYY
This is what you get when you use --create --assume-clean on disks
that are not actually clean... or if you somehow convince md to
integrate a disk that does not have valid data on, for example
because you copied partition table and md metadata - but not
everything else - using dd.
I didn't use that command or anything like that, i just triggered the rebuild with mdadm --run. It then started the restore (i monitored the progress by looking at /proc/mdstat), and it seemed to complete successfully.
Your best bet is that the data is valid on n-2 disks.
Use overlay https://raid.wiki.kernel.org/index.php/Recovering_a_failed_software_RAID#Making_the_harddisks_read-only_using_an_overlay_file
Assemble the overlay RAID with any 2 disks missing (try all combinations) and see if you get valid data.
Thanks, I will definitely try that!