Xbian hangs during boot saying "Switching root"

[mk01]

you are welcome.

the xbmc not starting will be part of the "freeze", attached / non-attached this particular disk (being written in fstab) and whether it was or wasn't mounted during boot.

if I remember correctly, /etc/init/xbmc.conf holds dependency for "local-filesystems".

as the usb will be mounted with usbmount, when recognized by udevd during boot, maybe better would be "noauto" instead of "nobootwait".

with noauto the disk won't be counted to as needed for "local-filesystems" condition to be fulfilled so the xbmc should start regardless of it. try.