Once unslung, the slug boots in a fashion where it is expecting to switch over to an external disk or flash device during boot. In this mode, it cannot unsling to an external device.
You can do one of three things:
a) reflash. Or,
b) attempt to unsling; the unsling utility will complain, reset the flag controlling the boot behavior, and prompt you to reboot, upon which you will then be able to unsling normally. Or,
c) remove the flag yourself by booting the device without disks, then removing the /.sda1root (or /.sdb1root) file, and rebooting, upon which you will then be able to unsling normally.
> I had a 300GB external enclosure attached to my slug, but things went
> bad with it, and I'm now using it elsewhere. I'm wondering, if I now
> plug a USB Key into the slug, can I just start from scratch and
> unsling to the USB Key? or do I need to repeat some of the initial
> steps? Thanks for the help