Mounting HAOS virtual disk image possible?

Installation
1

I have been running HAOS on Virtualbox. The Virtual disk imagefile is HAOS.VDI . After a borked restore of a backup, the VM is no longer functional. HAOS is no longer listening on port 8123. I need access to the backup file which is unfortunately only found in this backup located on this virtual disk. Somehow, Samba share did not upload the backup to my NAS last night, sigh.
Somewhere in this backup is the private key for one of my ESPHome devices, and it will essentially become a brick if I can’t recover this backup.

I was thinking of booting a live CD of Linux (say, Ubuntu), mounting the HAOS.VDI as second physical disk in the VM, and then trying to mount it and extract the data from that disk.

Any pointers on how to do this would be appreciated. In particular, which file system are the backups located in ? All other info welcome.

2

I booted Ubuntu 22 in a VM. I was able to mount hassos-data/supervisor/backup . In it were the tar files of the backups. I recovered them. Phew. Now if could only figure out why they aren’t restoring properly on Virtualbox.