Guide: Migrate from Virtualbox to Proxmox¶

Just a short guide on how to migrate a VirtualBox VM on Windows, to Proxmox.

Step 1. Convert .VDI to raw .IMG¶

To convert the VDI to a raw image, we can use VBoxManage.exe

This, is located in your Virtualbox install directory. I created a simple powershell script which will perform this task for you.

Note

Make sure you have enough space- The .IMG file created will be the FULL SIZE of the disk image.

If- you notice in my example, I am putting the output IMG on another disk, as my root disk did not have enough free space.

# This needs to be set to the exact path of VBoxManage.exe
$VBoxManage = "C:\Program Files\Oracle\VirtualBox\VBoxManage.exe"
# Set this to the source .vdi file for your VM.
$InputVDI = "C:\Users\YourUser\VirtualBox VMs\YourVM\YourImage.vdi"
# Set this path, to the output file for the raw disk image.
$OutputPath = "I:\Users\YourUser\VirtualBox VMs\YourVM\YourImage.img"

# No need to touch this.
. $VBoxManage clonehd --format RAW $InputVDI $OutputPath

The following output will be produced.

. $VBoxManage clonehd --format RAW $InputVDI $OutputPath

VBoxManage.exe : 0%...10%...20%...30%...40%...50%...60%...70%...80%...90%...100%
At line:5 char:1
+ . $VBoxManage clonehd --format RAW $InputVDI $OutputPath
+ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    + CategoryInfo          : NotSpecified: (0%...10%...20%....0%...90%...100%:String) [], RemoteException
    + FullyQualifiedErrorId : NativeCommandError

Clone medium created in format 'RAW'. UUID: 2915a341-0757-4315-982d-b48bdcd386a2

Ignore... the exception... Powershell does very odd things with stderr.

Step 2. Create a new proxmox VM.¶

No, special configurations are needed.

Do not use attach any boot media.

Nothing special needed here.

For disks- remove the default disk created. We will manually attach a disk via CLI.

Nothing special needed on CPU. Allocate cores as needed.

For memory, I personally always disable ballooning.

For network, I am not going to specify a NIC at this time. You can specify network as needed for your use-cases.

On the confirm screen, make sure "Start after created" is not checked.

You now have a new VM, without any storage, in a stopped state.

Step 3. Migrate the .IMG to Proxmox¶

Ok... make sure you have enough room to copy the disk to proxmox.

I ended up needing to take a detour to Delete the data partition from Proxmox

But- you will need to copy the .IMG over to one of your servers.

I ended up copying it to the ISOs share on my NAS, which is mounted to all of my PVE hosts.

root@kube02:~# ls -al /mnt/pve/ISOs/
total 10709368
-rwxr-xr-x 1 root root 4758700032 Feb  8 15:51  DiskImage.img

Step 4. Convert the raw image to QCow2¶

Suppose- you could do this before copying to your NAS/Hypervisor... But, now is as good of a time as any.

This- will take a while.

root@kube02:~# qemu-img convert -f raw -O qcow2 /mnt/pve/ISOs/DiskImage.img NewImage.qcow2

If... you are using a remote mounted share- it will have to read over the network. According to Unraid, it was reading around 2g/s.

QCow2 stands for QEMU, Copy on Write... It supports compression, snapshots, thin-provisioning, and a few other nice features.

The benefit here, is not having a 100G raw file.

Instead, we just have a 20G file, as that is how much data is actually used.

# Raw .IMG
root@kube02:~# du -h /mnt/pve/ISOs/DiskImage.img
101G    /mnt/pve/ISOs/DiskImage.img
# Qcow2
root@kube02:~# du -h NewImage.qcow2
20G     NewImage.qcow2

Step 4. Import the raw image to the new VM¶

We can use qm importdisk to achieve this.

You will need to know...

The VM's number
The name of the storage you wish to use.

The syntax is...

qm importdisk YOUR_VM_ID /path/to/your/raw/image NAME_OF_YOUR_STORAGE

root@kube02:~# qm importdisk 144 NewImage.qcow2  ceph-block
Use of uninitialized value $dev in hash element at /usr/share/perl5/PVE/QemuServer/Drive.pm line 555.
importing disk 'NewImage.qcow2' to VM 144 ...
transferred 0.0 B of 100.0 GiB (0.00%)
transferred 1.0 GiB of 100.0 GiB (1.00%)
... (truncated logs)
transferred 100.0 GiB of 100.0 GiB (100.00%)
transferred 100.0 GiB of 100.0 GiB (100.00%)
unused0: successfully imported disk 'ceph-block:vm-144-disk-0'

For me, this step took... about one minute. Ceph averaged 300-500MB/s

In proxmox, you will now see the new disk.

Step 5. Configure VM¶

Attach the disk. Click the unused disk, and click edit.

Set your desired bus, and settings, then click add.

I always use VirtIO when possible, as this provides the best performance using para-virtualized drivers.

The disk will now show attached.

Now, set the boot options. By default, it is set to ide2 (cd-rom drive). You can uncheck this, and select the new disk.

Step 6. Start VM / Done.¶

At this point, you can start the VM, and everything should work.

Congratulations, you have successfully migrated your Virtualbox VM to Proxmox.