I'm getting the "free up space" warning on my 32 GB HP chromebook (can't recall the exact model). When I look at the storage, the only thing that is obscenely large is system files. The exact "folder" sizes are:
"My files" at 6.9 mb
"Browsing data" at 15 mb
"Apps and extensions" at 139 mb
"linux storage" at 7 gb
"System " at 21.9 gb
I didn't have this issue until the other day when I used my chromebook to upload a youtube video from my micro sd card to youtube. I have also found it weird that when I go to the files app, it doesn't really show me much. Within the "my files" folder is only "downloads", "play files", and "linux files" folders. No files, and there never seems to be any files there (not within a folder), even when I have "show hidden files" on. There's also no offline files under the google drive section of my files.