Incorrect disk usage size

[Bruno Wolff III]

On Sat, Dec 20, 2008 at 18:37:41 -0600,
  Adam Flott <adam at npjh.com> wrote:
> After an aptitude safe-upgrade of Debian's testing (as of today) my root file
> system (ext3) seems to have "filled up" and I'm not sure how to get Linux to
> correctly report the used size.

Are you aware that there is space in file systems reserved for use only by
root? That may explain your confusion.

The purpose of the reserve is to allow a sysadm to allow some things to keep
working even if a normal user fills up a file system.

The size of the reserve on ext2/3 file systems can be changed with tune2fs.