du -h and df -h disagree on /

[Oliver Fuchs <oliverfuchs_(_at_)_onlinehome_(_dot_)_de>]

Hi,

I have a question regarding the output of df -h and du -h on my root
directory /
I am running OpenBSD 3.6 on a shared hardrive with WindowsXP and a second
harddrive with FreeBSD.
This is my /etc/fstab:
 /dev/wd0a / ffs rw,softdep 1 1
 /dev/wd0h /home ffs rw,nodev,nosuid,softdep 1 2
 /dev/wd0d /tmp ffs rw,nodev,nosuid,softdep 1 2
 /dev/wd0g /usr ffs rw,nodev,softdep 1 2
 /dev/wd0e /var ffs rw,nodev,nosuid,softdep 1 2

Now running df -h shows me this:
 Filesystem    Size   Used  Avail Capacity  Mounted on
 /dev/wd0a     194M   142M  42.2M    77%    /
 /dev/wd0h     6.3G   196M   5.8G     3%    /home
 /dev/wd0d     489M   8.0K   465M     0%    /tmp
 /dev/wd0g     9.8G   1.9G   7.4G    21%    /usr
 /dev/wd0e     194M  12.3M   172M     7%    /var

So the root directory / on /dev/wd0a is used with 142M of 194M.
But I think that this value is incorrect because du -h / shows me this:
196M	./home
10.0K	./tmp
1.9G	./usr
12.3M	./var
and for /dev/wd0a:
5.8M	./root
2.0K	./altroot
4.4M	./bin
11.3M	./sbin
34.0K	./dev
5.2M	./etc
4.0K	./mnt
2.0K	./stand
2.0K	./cdrom
plus the output of ls -axlh /
-rw-r--r--   2 root  wheel   770B Sep 17 19:59 .cshrc
-rw-r--r--   2 root  wheel   283B Sep 17 19:59 .profile
-rw-r--r--   1 root  wheel   5.1M Nov 28 17:41 bsd
-rw-r--r--   1 root  wheel   5.2M Nov 28 17:41 bsd.mp
-rw-r--r--   1 root  wheel   4.5M Nov 28 17:41 bsd.rd

So this is round about 50M and not as shown in df 142M
for /dev/wd0a.
I cannot find the answer to this disagreement but I have to points to made:
1) maybe it is depending on the fstab mount option softdep?
2) or is it because I copied some files from my FreeBSD harddrive over to
OpenBSD and this leeds to the wrong amount of df -h?

Thanx in advance for any help

Oliver
-- 
... don't touch the bang bang fruit