How do you determine whether system is running out of space?

1. By using DBC.Diskspace ,

Select 

sum(currentperm)/1024/1024/1024 "cur_space_gb" ,

sum(maxperm)/1024/1024/1024 "max_space_gb",

case when ((max_space_gb - cur_space_gb)/max_space_gb) *100  < 25

then  'Warning! Packdisk has to be run'

else  'No Packdisk activity required!' end

from DBC.Diskspace ;