cap = 6000 MB, used = 10MB, remaining = 1989.
6000 - 10 = 1989 ?
Do you not understand the meaning of the word offset? Are you not familiar with the exceptionally difficult art of rounding a number up or down? Perhaps you remember this from Sub A/Grade 1?
I think someone else missed Grade 1 completely
6000 - 10 = 5990
So a rounding error might give 5989, definitely not 1989!
What happen to the other 4001