Thanks Greg.  very synchro of you to send this to me: I've just spent the last 3 days trying to clone 18 to usb drive using dd and then tried installing to usb. I realized the dd failed because the target drive was smaller than the HD...Duh! So, the first thing I try today is shrinking the HD partition down to the size of the usb, and try the dd command again. This is supposed to be better than a persistent, forget why. But if this fails again (takes about 15 hours to complete) I'll try the link you sent.

So, been boning up commands etc and having massive frustrations following half assed posts. yesterday spent the whole day trying to install 18 onto usb, first attempt booted, but was real slow and most functions didn't work. I was successfull eventhought that attempt was flawed due to failing to format the efi partition with fat 32. So I followed the same procedure of installing required partitions with the correct EFI partition but kept getting the error that there was no root partition eventhough I followed the same directions as the first time and there was a large partition labeled and named /  and then tried ROOT. 

So, could not figure out why the I could not install 18 even after following the online directions for creating the appropriate partitions. And somehow it rendered my 18 live usb unable to boot afterwards. Had to download and burn another live....Good thing I don't have much hair left, I would have torn out most of it...

The good news is that finally got around to learning a bunch of basic commands

Thanks again.

On Sun, Dec 29, 2019 at 11:10 AM greg christ <dmarc-noreply@freelists.org> wrote:

https://www.howtogeek.com/howto/14912/create-a-persistent-bootable-ubuntu-usb-flash-drive/

https://www.howtogeek.com/howto/14912/create-a-persistent-bootable-ubuntu-usb-flash-drive/