Linux ships with a useful command named du (Disk Usage), which is used to determine the size of files and directories. When provisioning your server, Forge installs ncdu which is an advanced version of du that allows you to easily navigate your directories via an ncurses interface.
This is often caused by one or two large files that can be removed; however, locating these files is sometimes tricky. To find large files on your server, you may use ncdu to navigate around common directories on our server.
It’s safe to delete files within this directory but do not delete the directory itself.