Don’t do this, the node could be disqualified for losing data.
this is not needed, you may also call it like this:
df --si --sync
@Alfred Right now without a reformat the only way is to reduce an allocation to what’s used or even below that. If the customers decide to remove their data, it may reduce used space on your node.
You could try to go with gparted or LVM, but you will lose data and/or node in case of any issue with hardware, power supply or on user error, see my adventure on such case: Moving from Windows to Ubuntu and back