I am moving an LXC disk to a directory from LVM-thin, on the file system I see the disk has been copied fully (full size):
The disk file keeps getting updated all the time if I refresh the directory, size doesn't change.
The moving volume doesn't complete. It is just stuck.
I'm not sure why.
I can't 100% remember now, but I think I wasn't using a tmp folder for dumps, and local was over overprovisioned/full.
I had various issues with backing up this LXC as well given the size, transfer speed, etc. But is acceptable now.
I only wish Proxmox looks at incremental backups so save time and expense on hardware!