Finding where was free space gone and who that guy that should be cleared on a server can be a challenge
Unix as I know has no usable UI tools for that, but there is a console that has power.
How to find folders for cleanup on Unix/Linux/Ubuntu?
Here is a command for grepping folders/files that has Gigabytes of size
du -c -h | grep -P "G\t"
The same for Megabytes as well, but I guess not so usable at admin level, mostly good for user folders.
du -c -h | grep -P "M\t"
And here is a sample output for the first command