[Wylug-help] Removing RAID Superblock

[Dave Fisher]

Hi,

I've been tinkering with Linux software RAID and got myself in something
of a jam.

I thought that I had safely failed and removed all the partitions in each of
my arrays, then deleted the arrays themselves.

Unfortunately, despite re-writing the partition table with fdisk,
whenever I boot from a rescue CD, the system still creates /dev/md0 and
/dev/md1.

For example

  mdadm --detail /dev/md0 

shows 'active synch' for /dev/sde2 and states that the superblock is 'persistent'

It would appear that I can't remove the remaining device (e.g.
/dev/sde2) in either array, because they are 'busy'. 

Is there a way to:

  a) boot without activating /dev/md0 or /dev/sde2 ?
  
  b) deactivate /dev/sde2 in order to fail then remove it? 
  
  c) Or is there some other method that I haven't noticed in the
  copious, but decidedly fragmented documentation?

Dave