When using a tool suck as SysRescCD to access data on alien drives you may find you need to disable the RAID (i.e. to allow you to do a block level copy).
First you need the system to recognise the RAID devices.
mdadm --examine --scan > /etc/mdam.conf
(ensure you only use this on a SysRescCD and not on a live server otherwise your exisint gfile will be modified)
You will now be able to stop/start the raid devices as normal
mdadm --stop /dev/md0