Questions[boot-to-ram](ubuntu)

I'm using Xubuntu 20.04 LTS live USB (non-persistent) and I just tried the toram option. It got stuck on the logo screen (or so it seemed) so I force shut down the computer.

Now I booted normally without toram and while I was working on the computer, I accidently removed the USB but to my surprise, everything is working normally. I mean, shouldn't it hang/freeze. Is this normal?

How can I make sure whether I'm running Xubuntu on ram or USB. And if it turns out to be from ram...how? Did I permenantly load Xubuntu to my ram? I thought everything gets deleted once I restart. If that's not the case, how can I delete is from ram?

Thanks for any help guys!

Summary of the Problem

I've created a custom ram-only Ubuntu image that refuses to boot over USB on any device. Before I encrypted it and used a loop device, it worked well. With the encryption setup, it will boot without issues from a burned DVD as long as the drive is over SATA and not USB. Initially I thought it must be a BIOS configuration issue with booting from USB, but this is not the case as it displays the same symptoms when run on any device and with legacy usb boot properly enabled. It always gets to the grub menu, so usb boot is working.

I used the answer from this post to successfully encrypt my squashfs and set it up using losetup.

This is what I get when I attempt to boot from USB or DVD attached via USB:

/init: line 7: can't open /dev/sr0: No medium found

This spams over and over again until it drops you into the initramfs cli.

Here's what I've tried with no success:

• Enabling usb_storage and many other modules in /etc/initramfs-tools/modules during boot time
• Using isolinux instead of /boot/grub.
• Referring to the linked answer (same as above), I modified the casper files to mount to /cdrom instead of /mnt.

Afraid I'm grasping at straws here with my limited understanding of the initramfs boot priories/files. Any thoughts would be appreciated!

Additional Information

os-release: Ubuntu 18.04.4 LTS

kernel: 4.15.0-91-generic

I have a machine with 10 GB of RAM, and I would like to run Ubuntu on it (Debian also OK if its easier), fully in RAM in such a way: I boot from a compressed image on an USB flash disk, that is uncompressed into RAM, and then I can remove the disk from the USB slot, and use the system only with RAM, without any permanent disk.

Whenever I make any changes that I want permanent, I would put the flash disk back into the USB slot (possibly not the same one as I used initially to boot, as I would like to keep many versions of the boot flash disk), and run some command that would save the current state into a compressed image on the disk.

How can I set this up?