You can check inode usage using df -ih. I can’t do anything, I got error for using bash-completion, you cannot do anything unless you remove something.

You can check folder that using inode partition with find / -xdev -printf '%h\n' | sort | uniq -c | sort -k 1 -n, read this for explanation.

Here list how I solve the problem:

  1. Removed old backup
  2. Remove folder/file from software that you not use anymore (in my case I remove apache folder because I move to nginx recently)
  3. Remove man pages (please check this for explanation),
  4. Remove app cache, remove cache from your web apps
  5. Remove old kernel (I remove manually using rm -rf)
  6. Reconfig logrotate

Please doing some research before doing something that can affect your server, good luck