Increasing the disc image allows the disc now to grow to the new size of 20GB instead of the old size of 6GB.

As qcow2 disc images are only as big as the data stored inside the disc image, the filesize will be not effected by the resize operation. The disc image connected to virtio0 is now increased in size by 14 GB. To actually resize the disc image from the console, qemu provides this easy command. The Proxmox web interface will simply show a message like this giving no clue about the actual reason. VM 104 qmp command 'block_resize' failed - this feature or command is not currently supportedĪt the time of writing, the Proxmox web interface is sadly not reporting this situation back to the user with all the details. You will notice a error message like this in the console. The output above shows an example of an image with snapshot. A disc image with a snapshot is not resizeable. Another limitation is the snapshot feature. One of those is that it is not possible to decrease the disc size. Resizing a disc image has a couple of limitations. With the VMID and the disc-bus information (virtio0) inside the VM, the disc can be resized. To check the Disc image details you can execute the following command. The important information from this command is the identification of the disc-type which is in this example “virtio0” representing the first disc connected via the virtIO bus. The following command will show more details about the VM, including the disc type and size. Proxmox uses qemu for the KVM virtualisation which provides a variety of information about the VM. The following Command will create a compressed archive of the VM with all its configuration and data. Proxmox provides great tools for this right out of the box. At this point I suggest that you consider creating a backup of your VM in case something goes wrong.

Proxmox decrease disk size