Today the “/tmp” directory was full on a server because of a huge log file. When I checked it with the command “df -h” is saw that the directory used 100% of disk space. After I removed the log file, “df -h” still displayed the same value. I thought that it might be a caching problem, but the fact is that deleting a file name doesn’t actually delete the file.
It is not visible anymore if you execute the command “ls -sal”, but if some other process is holding the file open, it is not really deleted.