Disk Utilization

Hi,

Anybody know's which parameters evaluate the AppManagger, in order to show the graphs for Disk Utilization, for example, I have a Server sun and I have the next out

$ df -k
Filesystem kbytes used avail capacity Mounted on
/dev/md/dsk/d0 20655529 3780177 16668797 19% /
/proc 0 0 0 0% /proc
mnttab 0 0 0 0% /etc/mnttab
fd 0 0 0 0% /dev/fd
/dev/md/dsk/d3 6198606 477091 5659529 8% /var
swap 8946464 32 8946432 1% /var/run
swap 8946608 176 8946432 1% /tmp
/dev/md/dsk/d6 12442252 1653587 10664243 14% /WAS502_Logs
/dev/md/dsk/d5 12442252 7656052 4661778 63% /WebSphere
/dev/md/dsk/d4 10327372 10258 10213841 1% /var/crash

If I calculate average for this, I dont have the same quantity, that in the web page (AppManager)

Anybody can explainme, please?