I installed Ubuntu server from a USB stick onto another USB stick. First I tried using a 4GB thumbdrive that was lying around and quickly ran out of space trying to install software, half the drive was used by swap. Then I went with a 16GB drive which has plenty of extra space.
After installing it was up and running great, until I moved the USB drive. Then it would not boot no matter what. Just loads to the bios screen and the boot menu shows this drive as an option but choosing it will not boot.
To fix it, I re-inserted the install USB and chose “install ubuntu” again. Then it gave me some options about the existing system including an option to install grub boot loader. Doing that resolved it.
Seems to be a uefi issue with the mobo (ASUS Z170).
Also not able to get the onboard wifi (“wifi Go”) to work with Ubuntu, but the manual does say it requires windows. darn.