Why does `df` lie about free space

[Rob]

Kyryll A Mirnenko wrote:
>   That's an old problem, but yesterday I was working with 1.4G UFS2-slice 
> reported by `df` to have 400kb of free space. Alternative calculations (e.g. 
> writing a random file until kernel says no inode's free) give a result of 
> more that 100M (!) unused. Thats about 7% of the whole size!
>   So whats wrong with `df`?

Read "How is it possible for a partition to be more than 100% full?"
at

http://www.freebsd.org/doc/en_US.ISO8859-1/books/faq/disks.html

R.