df question

[Osmany Guirola Cruz]

Hi people

I do df -h on my machine and got this RARE ouput

%df -h

Filesystem     Size    Used   Avail Capacity  Mounted on
/dev/ad0s1a    7.7G    2.2G    4.9G    31%    /
devfs          1.0K    1.0K      0B   100%    /dev
/dev/ad0s1d     65G    9.5G     50G    16%    /usr/home

%df
Filesystem  1K-blocks    Used    Avail Capacity  Mounted on
/dev/ad0s1a   8122126 2328406  5143950    31%    /
devfs               1       1        0   100%    /dev
/dev/ad0s1d  68372608 9940308 52962492    16%    /usr/home



50G+9.5G=60.5G   but the partition size is 65G ... where are my ~5G,?
What can i do?
Thanks
Osmany