If a VM is build using qcow2 or vmdk HDD format with size say 1TB and fill it up completely, it uses 1TB of Proxmox server disk space, but when you delete files from VM, it does not de-allocate HDD space and still 1TB of disk is used on Proxmox disks.
I faced this problem on 4.0 and 4.2 PVE. Storages are added in "Directory" and "LVM -Thin" and nothing changed.
I faced this problem on 4.0 and 4.2 PVE. Storages are added in "Directory" and "LVM -Thin" and nothing changed.