Hi,
do you get an error when it reaches 50 GB? The next iteration shouldn't start until the previous one is finished, so this sounds strange. What is your pveversion -v? When you run ps faxl, can you share the "tree" of each pvescheduler and pvesr at the top level? That is the line with the command name and everything below prefixed with ASCII-art like \_, until the next top-level entry.