I wanted to get a test version of Linux (with a GUI) up and running for a friend who wanted the first experience of Linux.
But most of the "Live" versions out there want to take over the booting of what ever PC they were on.
This was beyond my friends capacity and I had no idea which computer it might be used on, so that was out of the question.
I settled on a USB version of a "Virtual Machine" called Portable Vitrualbox. Virtualbox being the VM environment created by Oracle.
This enabled me to load what I thought were very low images of Linux into the USB, along with the VM program, which Tibo had altered so everything stayed on the USB.
The only use of the Host Windows computer was its RAM and access to the Internet.
So everything would be back to normal, untouched by Linux or the Virtual Machine on removal of the USB.
One problem I encountered was that the VM software was well documented, but the Portable version was not.
If you ran it as it was installed it crashed as it had no default operating system, or the operating system was on the computer you installed it from, and was left behind when you moved it to another computer.
What you needed to do was to find some Linux ".iso" images which were small enough to load on a USB memory stick.
I found three Puppy Linux, Porteus and Linux Mint (Although Linux Mint was nearly 2Gb long, larger USB sticks are available to keep up).
The other thing was when running the VM software was to install a CD-ROM on the IDE drive, along with the location of the ".iso" file you wanted to run "Live". This had to be a directory on the USB stick!
A default IDE hard drive was included in the setup of 2GB, but this was a Virtual drive, so initially it only took up 2Mb, but could expand to its maximum capacity if required. So the limit was the size of the USB stick which found was a minimum of 4Gb.
The Virtual Machine could then be "Started" by using the start button and immediately went to the CD-ROM as the virtual "Hard drive" was empty.
It then ran the "CD-ROM" ".iso" file and booted Linux, depending on which copy you had setup.
The instructions were not always clear, you had to watch out for the notes on passwords required for the system, as they wizzed past, which were always different. But if you let it go nine times out of ten it would install to a GUI desktop.
Then you could use the mouse to change the default setting, that would last this one session.
I always managed to run a browser and access the Internet and managed to run Linux based Office programs, if supplied on the ".iso" file.
On exiting the VM you could leave as it was and return later to its suspended state, or you could power it down and it would loose all the settings and start a new session from the "CD-ROM".
Installing ANY Linux system on to the small virtual "Hard Drive" seems to be out of the question as it quoted tens of Gb's to install the full programs, and required many more disks than the first "iso" file supplied.
So having the "hard drive" partitioned and a swap drive added was a bit of a waste of time, as it was never used, but the VM software assured me the VM software would fail to start if it was omitted.
The advantage of the Portable version is that all the references to any software location are made "relative", so they stay within the USB drive and are not referred to by drive numbers, once setup.
So you CAN run Linux, with limits from a USB stck, but it will get hot, due to the accesses made by the software and eventually you will have to re-format the drive and re-load the software, as it leaves many damaged file headers all over the USB stick, which makes it impossible to transfer files to it.
You do NOT need a bootable USB, in fact it takes up space you could use for the "iso"s.
You DO need to format it to "FAT32" and make sure there are no dud sectors, so I would not use the "quick format" option in Windows.
You then need to load Portable-VirtualBox.exe on to your chosen USB mmory stick. After running it for the first time it will download VirtualBox from the Oracle website and install it untouched.
You then need to exit the software and load into the folders on the USB stick, the "iso"s you want to try out.
Re-run the Portable-VirtualBox.exe program and set it up as detailed above, to get a working system.
The references are:
Portable-VirtualBox.exe from http://download.tuxfamily.org/lilicreator/virtualbox/5.X/
VirtualBox from Oracle (which can also be used the main hard drive of a PC, not just a USB). https://www.virtualbox.org/wiki/Download_Old_Builds_5_2. This where Tibo gets his from.
Pendrivelinux.com which has the various flavours of Linux and their installation. https://www.pendrivelinux.com/using-a-portable-virtualbox-to-run-linux-from-usb/
A very Merry Christmas to All!