In this small tutorial, I will explain how to simply mount a VDI image to Ubuntu. I guess it should work on most Debian based distribution.
I had to do this trick because I used for a long time a Kali VM on VirtualBox and I stored a lot of files on it. But one day, after an update, I was impossible to reboot my Kali VM. So to avoid loss all my documents on this VM, I mounted the virtualBox Image on my Ubuntu.
In my case, Ubuntu version was 18.04.3 LTS but I tested the solution with 16.10 too.
First we need to install QEMU tools using the following command:
sudo apt install qemu-kvm
To be able to mount the VDI disk, we need to load the network block device module (nbd) using the following command:
sudo modprobe nbd
Now, we can run the tool qemu-nbd on the VDI file. This tool is a user space loopback block device server for QEMU disk images.
qemu-nbd -c /dev/nbd0 [path-to-vdi-file]
Replace [path-to-vdi-file] by the path towards your VDI image. After that, you “linked” your VDI to this virtual block device (/dev/nbd0).
You can check the partitions in the image using the following command:
sudo fdisk -l /dev/nbd0
This command will check the entire image as a block device named /dev/nbd0, and the partition it as subdevices. In my case, I can see 3 different partitions:
sudo fdisk -l /dev/nbd0 Disk /dev/nbd0: 40.4 GiB, 43365695488 bytes, 84698624 sectors Units: sectors of 1 * 512 = 512 bytes Sector size (logical/physical): 512 bytes / 512 bytes I/O size (minimum/optimal): 512 bytes / 512 bytes Disklabel type: dos Disk identifier: 0xeadb4be2 Device Boot Start End Sectors Size Id Type /dev/nbd0p1 * 2048 37748735 37746688 18G 83 Linux /dev/nbd0p2 37750782 41940991 4190210 2G 5 Extended /dev/nbd0p5 37750784 41940991 4190208 2G 82 Linux swap / Solaris
Now, you just have to mount the desired partition on your system. In my case, I only need to mount /dev/nbd0p1 to retrieve my files. I mounted it to /mnt directly.
sudo mount /dev/nbd0p1 /mnt
Now you can check the content of /mnt and you should see the content of your partition.
ls /mnt bin home lib32 media root sys vmlinuz boot initrd.img lib64 mnt run tmp vmlinuz.old dev initrd.img.old libx32 opt sbin usr etc lib lost+found proc srv var
After completing your work, you can unmount the partition using the following command:
sudo umount /mnt
Don’t forget to shutdown nbd service (the server) and remove the ndb module from the kernel
sudo qemu-nbd -d /dev/nbd0 sudo modprobe -r nbd
Hope it can help 🙂