I was working on a web-server which we recently purchased. There wasn’t much data on it yet, but when I tried to upload some of files onto the server I started receiving an error saying that there wasn’t enough space left. And when I checked remotely, using df -h I noticed that 100% of the space was used. After the panic session, I started looking for the cause and the solution was quite a simple one.

Open Home > Disk Usage Analyzer

Here, I noticed that 90% of the space was occupied by the .cache folder
In .cache there is a folder called deja-dup which took up most of the space. Now if you are wondering what this is, this is a folder created by Backups in Ubuntu when you try to create a backup locally. Apparently, deja-dup occupied a ginormous amount of space on the machine.

Making sure I have a recent copy of the Backup available, I deleted the deja-dup folder and voila, problem solved.