On Mon, 22 Oct 2001 at 18:25, Juan Miguel Cacho wrote: > Or, du does not report superblock usage; it only reports file and > directory size.
This is correct. du vs df reports WILL differ, and it's not because of corruption. du will go through each file and report the contents of that file. A directory per se does not occupy space as far as du is concerned (although of course occupies space as far as the filesystem is concerned, and what takes up this space varies depending on what filesystem you use). Instead du will go through each file in a directory and return the sum of the file contents of that directory. Take this example: jijo@gusi:~$ du -csb notes 8192 notes 8192 total jijo@gusi:~$ cd notes jijo@gusi:~/notes$ mkdir test cdjijo@gusi:~/notes$ cd .. jijo@gusi:~$ du -csb notes 8192 notes 8192 total jijo@gusi:~$ cd notes/test jijo@gusi:~/notes/test$ mkdir test jijo@gusi:~/notes/test$ cd ../.. jijo@gusi:~$ du -csb notes 8192 notes 8192 total Notice how the size of the notes directory did not change as far as du is concerned. But the two test directories had to take up space, right? Their names, the date they were created, and the first test's contents had to take up space. Of course they take up space. Metadata space, that is. And du does not count metadata. df, on the other hand, will ask the filesystem about usage. df will therefore include usage of such things as the superblock, metadata, the journal, et al. For this reason, as your filesystem varies, so will the results of df. du, however, should be quite consistent (assuming your data doesn't change). SUMMARY: 1. du will be more accurate if you want to know how much data the files have, and thus the space that data actually occupies. 2. df will be more accurate if you want to know total disk usage of a particular filesystem, and how much actual disk space is available. --> Jijo PS- note to self: add FAQ entry. ;> -- Federico Sevilla III :: [EMAIL PROTECTED] Network Administrator :: The Leather Collection, Inc. GnuPG Key: <http://jijo.leathercollection.ph/jijo.gpg> _ Philippine Linux Users Group. Web site and archives at http://plug.linux.org.ph To leave: send "unsubscribe" in the body to [EMAIL PROTECTED] To subscribe to the Linux Newbies' List: send "subscribe" in the body to [EMAIL PROTECTED]
