LVM-Thin - remove whitespace from VM disk

Let s say I have a VM running on PVE, which stores some files for me. For the sake of the example, we ll say that it is 100GB of DMG files and 50GB of PDF files, on the same virtual disk located on a LVM-Thin volume. I use PVE s built in backup solution and save the backups to a regular SMB share on an offsite NAS, and the backup is roughly 150GB in size. One day I decide that I do not need the…