Free space for overload of data

When I install node the software ask 10% make free space on node for over data. It ask 10% of all space. I made it. But what the 10% overload? Can it be and what to do if overload will be more?

It is meant for a variety of reasons: database size, giving the file system some space to be able to do it’s job (the more filled up the drive, the slower it becomes), and there might be some more.

Plus we could introduce a bug and the node could mistakenly use more than allocated.
So it’s better to have some free space to do not broke your node: if there is no more free space, the node even could not start.