The host system start in Live-mode.
The swap is not loading.
Swap file is not created (swap-file-creator)/
When starting guest-systems (other) in virtualbox, after a while the system freezes. No commands can be executed. Just a hard reboot.
Is there a connection between this event (freeze os) and the launch in live-mode?
If it does not free in persistent mode, then this could be the case.
How much (free) RAM does the host operating system have?
So you did boot in host live mode… Did you then start VMs in live mode or “persistent” mode?
When starting the host in host live mode it’s not really needed to start the VMs in live mode. I don’t think we currently make this clear in documentation. But perhaps starting VMs in “persistent mode” wouldn’t be really persistent since the host is already booted in live mode would help.
Well, usual host optimizations might help. Such as installing a light desktoip environment and/or stopping services that aren’t required but taking RAM. (If there are any.)
Try to monitor RAM and see if it fills up. If that is even the issue. Try to see if RAM fills up before the freeze. You can monitor RAM usage with many tools, ksysguard comes to mind.
This is normal. It can be modified with overlay-size kernel boot parameter in GRUB.
See:
man live-boot
overlay-size=SIZE
The size of the tmpfs mount (used for the upperdir union root mount) in bytes, and rounded up to entire pages. This option accepts a suffix % to limit the instance to that percentage of your physical RAM or a suffix k, m or g for Ki, Mi, Gi (binary kilo (kibi), binary mega (mebi) and binary giga (gibi)). By default, 50% of available RAM will be used.