[Resolved] Migrated VDI does not boot

[zadiste]

I recently switched my host from Ubuntu 18.04 to Debian 9. I copied the "Virtual VMs" folder so that I could reload my virtual machines. However, every one of my 4 VMs fails to boot. It will just load a black screen with a blinking cursor. I know this problem has occurred for other forum users, but the stated solutions for those issues did not work for me. Here are the details:

Virtualbox version 6.0.4
Guest Additions is installed on the guest
Host: Debian 9, 64 bit, 4GB of RAM
Guest: Windows 7, 32 bit, ~1 GB of RAM
VM log is attached.

I've also tried two other methods of accessing the VDI. First, I tried using the Windows installer ISO to "repair" the guest OS, but it produced errors that files were missing from /boot and would not run. Second, created a new VDI with a fresh install of Windows 7 and connected my old VDI through a SATA port. From the new OS, I could not access the information on the old VDI. My goal, however, is to get my original VDI to boot, not to just recover the files on it.

Any suggestions are much appreciated!

[andyp73]

00:00:03.361575 VMMDev: Guest Log: BIOS: Booting from Hard Disk...
00:00:03.367887 VDI: Out of range access (5356560384) in image /home/zad/VirtualBox VMs/Windows 7/Windows 7.vdi, image size 4294967295
...
00:00:03.450719 VDI: Out of range access (5356944896) in image /home/zad/VirtualBox VMs/Windows 7/Windows 7.vdi, image size 4294967295

My guess is that you copied your VMs folder via an external USB device that was formatted as FAT32 which is limited to a 4GB file size. As a result all of your .vdi files will have been truncated.

You should be able to verify this by going to the top level folder of the VMs and running the command:

find . -name *.vdi -exec ls -lah {} \;

I expect that it will show that the file size for all of them is 4.0GB.

mpack is probably the most qualified regular poster when it comes to vdi files so he may have some magic to be able to fix them to at least be able to get some of the files out but in all likelihood if you don't have pre-existing full sized backups then I think your data is gone.

-Andy.

[zadiste]

Yup, you're right! My backup drive is formatted to FAT32 and all my VDIs are at 4.0GB. Thanks for the help!

It's not a major loss for me since I didn't have any important files on them. I just have to set up those VMs again. I'm just glad to know what I did wrong.

[socratis]

Marking as [Resolved].
Nice catch Andy!

[BillG]

Indeed it was. So obvious (once it has been pointed out)!