I want to do this so I can set up a friend to play with LM without the restrictions of a live session but without him having to install a dual boot. Of course, a USB system will be much slower, but this is simply a trial. If he likes, he'll do dual boot later (probably using two drives rather than partitions).Of course, you could just install a full version of Linux Mint onto a USB stick very easily, but you would need a 16gb or greater USB flash drive. This is what I have done for a portable full version of Linux Mint that can be updated, programs installed, utilities installed, etc... You just create a normal live DVD or USB flash drive of Linux Mint, then put the USB drive that you want to install a full version of Linux Mint onto into a USB port (or another USB port), boot up to the Live DVD or Live USB flash drive, double click the install desktop icon, and when asked where to install, select the other USB flash drive.
So, I opened a live session, plugged in a USB drive and started the install, selecting "Something else" for installation type. Chose the USB drive (/dev/sdc) in the first dialogue box and also for installation of boot loader. Hit "Install" and got error message: "No root system is defined". Tried clicking "New Partition Table ..." button, but that just bounced me to sda (my hard drive), which I very definitely don't want to modify. For the visually inclined, here's a screenshot:
Probably this is obvious and hopefully it's simple. What does the installer want me to do? Or to have done, say with GParted, before running the installer?
Tried searching the archive, but the terms are too common to zero in on this particular topic.