How to Delete a Proxmox VM Disk
- Delete a VM Disk via GUI
Select the virtual machine from the resource tree and open the Hardware tab.
Click the disk you want to delete.
Then, use the Remove button to instruct Proxmox to delete the disk.

Confirm you want to remove the disk and permanently erase all data with Yes.

2. Delete a VM Disk via Command Line
List basic information of all the datasets on the system with:
zfs list
The output displays the names of the datasets and the values of their used, available, referenced, and mounted properties. For instance:
rpool/data/vm-100-disk-1 10G 5G 10G -
To delete a disk via the command line, run:
zfs destroy -f [disk_path]
Therefore, to delete the above mentioned sample disk, run:
zfs destroy -f rpool/data/vm-100-disk-1