There is still ongoing discussion, as the patches are in an early stage so which storage types are going to be supported cannot be answered just yet, see e.g. https://lists.proxmox.com/pipermail/pve-devel/2024-January/061519.html
Hi,
the storage where VM images are on doesn't matter. The storage for the fleecing images needs to be capable of thin volumes or sparse files and support discard. LVM-thin does both and is very likely going to be supported. Storages without those features will require much more space usage and we're still discussion whether we should simply prohibit those or only recommend/warn against (some users could might still want to use such a storage if the space usage is not an issue for them).
the storage where VM images are on doesn't matter. The storage for the fleecing images needs to be capable of thin volumes or sparse files and support discard. LVM-thin does both and is very likely going to be supported. Storages without those features will require much more space usage and we're still discussion whether we should simply prohibit those or only recommend/warn against (some users could might still want to use such a storage if the space usage is not an issue for them).