Cannot find what is filling up disk space /dev/vda1 is 100% full

Another option that might help you find out what is using up space is ncdu Install it with:

sudo apt-get install ncdu

If you still can’t find anything, try running:

lsof / | grep deleted

Sometimes if a file is deleted while it is opened by a process, it will not actually free up the disk space until the process is ended. This command will show if there are any files in that state.

outside of other answers here what I did was:

navigate through subfolders with ncdu and finding large folders. Among them one can delete:

/var/logs https://bbs.archlinux.org/viewtopic.php?id=158510 // /var/logs/journal http://askubuntu.com/questions/100004/how-can-i-free-space-from-a-massive-39-5gb-var-log-folder // other already archived (GZ-ipped) files;

and compress .git folders of projects by shrinking them with this command: git repack -a -d --depth=250 --window=250 http://stackoverflow.com/questions/5613345/how-to-shrink-the-git-folder

Googled and found this question which had the same problem.

@TonyTsang That command helped me find what it was

Apparently it was a hidden log folder set by pm2.