I'm currently using Chrubuntu on my C720 Chromebook, but want to create a bootable Linux USB key. The problem is that I can't seem to do this from within Ubuntu once I've loaded it and obviously can't do it in Chrome OS at all.
I haven't got easy access to Windows or a Mac, so would prefer to do it within Chrubuntu if possible. I've tried it with both an SD card and a USB thumb drive with UNetbootin and the disk creators available through the software centre. Both throw errors, basically telling me I don't have permission, or just "Installation failed".
Right now, I have a downloaded ISO and a 32GB SD card and USB key.
The reason I'd like to do this is that I need to do some software development for university (the only serious programming this academic year) and would like a bootable environment for both my Chrome devices and for use elsewhere.
Any help would be appreciated.