VirtualBox VMs get destroyed

General system Applications
1

After last system update I tried to start one of my VMs it shows that no boot medium is available.
Some other VMs in the list have a message that they are not available.

Sometimes I can start a VM and work in it for a whole day. But after shutdown I cannot start it anymore.

Here is my system config: https://0x0.st/8Sh_.txt
The update after this problem occur was on friday 2025-03-07
The special thing with my config is that I have an encrypted btrfs mirror - which worked fine for some years now.
The directory for the VirtualBox Vms has the C attribute as is recommended for VMs.

The rest of the system seems to work normal. No broken files or other issues till now.

Any ideas?

Best Regards
Volker

2

Not familiar with what this means?

3

This means disable copy on write for VMs because in makes no sense with bit virtual disk files.

4

We need more details about this message “no boot medium is available”.

Please show us the original error message.
Which boot media is configured for the VM? Is it possible to share the whole vm config as a text file?
What exactly is the file / folder structure? Please post output of “ls -l” of relevant folders.