Migrate from https://cmakerhk.wordpress.com/2018/10/13/install-on-external-hdd/
How I made it:
the ubuntu iso only create the boot part –> therefore, it has no OS inside and the file is quite small.
How I fail ::
I use rufus/etcher to burn iso on External HDD, and the installation of the OS require remapping on the memory address, therefore, it crash on these scenaio.
I use one more USB (16GB) to be burnt by rufus, and install that ubuntu on my 1TB external HDD, and this success.
The error message won’t tell you this, you need to go and explore by yourselve.
–> partition software, https://www.partitionwizard.com/ by miniTool
–> Flashing software: rufus/etcher
Many tutorial and youtube won’t help, since they don’t give you the big picture.
It is similar but not the same on flashing with raspberry pi(ubuntu Mate) and ubuntu Desktop
On Ubuntu Mate(pi), you flash the image on to the SD card, and everything is done.. the OS is already installed on the SD card.
However, in ubuntu Desktop, you need to have the installation USB, and a harddisk to make it work.
If needed self-parti:
swap area 512 MB
/home 20000MB
/ the rest of your HDD
will do
ref: https://askubuntu.com/questions/343268/how-to-use-manual-partitioning-during-installation
Hope you can do it. happy Linux