I have a Debian Wheezy install that is currently showing 100% disk usage, yet the files in / do not seem to add up to the sum of the disk as reported in a df -h output (as tested with a du -sh /). I have since rebooted, so this would have cleared out any open files that could have been deleted but still remained open.

Output of mount:

/dev/disk/by-uuid/blahblah-3431-43i9-ac71-blahlah on / type ext4 (rw,relatime,errors=remount-ro,user_xattr,barrier=1,data=ordered)

Output of df -h:

rootfs                                                   36G   33G  810M  98% /
/dev/disk/by-uuid/blahblah-3431-43i9-ac71-blahlah   36G   33G  825M  98% /

Output of du -sh of / (excluding media, as that dir has directories mounted from other drives):

# du -sh --exclude=media *
7.4M    bin
18M     boot
0       dev
11M     etc
13G     home
0       initrd.img
116M    lib
4.0K    lib64
16K     lost+found
4.0K    mnt
341M    opt
du: cannot access `proc/5744/task/5744/fd/4': No such file or directory
du: cannot access `proc/5744/task/5744/fdinfo/4': No such file or directory
du: cannot access `proc/5744/fd/4': No such file or directory
du: cannot access `proc/5744/fdinfo/4': No such file or directory
0   proc
134M    root
1.1M    run
7.6M    sbin
4.0K    selinux
4.0K    srv
0       sys
56K     tmp
6.4G    usr
2.4G    var
0       vmlinuz
  • 1
    When you run du add an x parameter to it and it will run on a single filesystem. That way you won't need to exclude anything and output will be clearer. Did you try to run fsck on that filesystem?
    – grekasius
    Jun 29, 2014 at 9:07
  • 1
    Also, don't forget the dotfiles at the root level; including .[A-z]* as an additional argument to du can often shed light on directories like .hugecache (example invented for illustration).
    – MadHatter
    Jun 29, 2014 at 9:09
  • Possible duplicate of serverfault.com/questions/57098/du-vs-df-difference
    – HBruijn
    Jun 29, 2014 at 9:35
  • I tried passing -x to du and it provided the same result. Also tried looking for [A-z]* as well as "du -sh .*" to no avail. Even when I am in / and attempt to tab complete from ".", it only presents 2 files of which are only a few kilobytes.
    – Peter
    Jun 29, 2014 at 9:39

1 Answer 1


It's possible that even with a restart that something is creating and holding the files. Do a lsof | grep deleted or something to that effect to view the (deleted) files.

Also, a great program to track disk usage is ncdu. With ncdu -x . you won't miss any files and it won't traverse the partitions.

  • Thank you! The lsof didn't return much but I had some luck with ncdu. It shows that my media directory actually contains 10.5G of data! It would seem I accidentally copied some data to the root filesystem rather than mounting, like I do with my other dirs in /media . Good thinking, Vladimir, and thanks all. :)
    – Peter
    Jun 29, 2014 at 12:20

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