David Wright said: > > Bear in mind that du can also seriously underreport usage when run > as a user because of permissions (whereas df is always right).
Besides files hiding `under' mount points, there is another type of file that is invisble to du. If a file which is opened by a process is removed, it is not really removed from the disk. As long as the process keeps the file open, it is a valid file (to that process). As soon as the file is closed, the disk space is freed again. Some programs use this fact to make sure that temporary files are cleaned up even if the program crashes: they open a scratch file, and immediately remove the link from the disk. Then the process has an open file that not even root can read (unless with a disk editor), which disappears from the disk as soon as it is closed. Sometimes this technique causes hard-to-understand filled up /tmp partitions if daemons have a leak towards a tmp file. It then helps to stop/start long running daemons to identify the problem. HTH, Eric -- E.L. Meijer ([EMAIL PROTECTED]) Eindhoven Univ. of Technology Lab. for Catalysis and Inorg. Chem. (SKA)