Changing non-raid drive, breaks Raid

Hi All

I have configured my server with 8x 2TB drives as Raid 6 as per the video posted here - Title as per this post - Title
At the time i asked the question, creating a raid using - /dev/sdx, will the raid not break if i add or remove non-raid drives as Linux does not preserve the /dev/sdx numbers, "seen this movie before..."
Now it is broken... i replaced one of my non-raid drives to copy data to the Raid, and now it boots to recovery mode.
I have no idea where to start looking, any help will be appreciated.

The other thing i noted is that my 2nd NIC is also "dead"

Z