I was looking for how to use cvs compression inside NetBeans and I have just found the following message from Peter Pis:
On Mon, Jul 3, 2006 at 12:47 PM, Peter Pis
try to run netbeans with switch "-J-Dnetbeans.experimental.cvs.io.compressionLevel"
Level range = <0,10)
It is really old but thanks to GMail I still have it and the NetBeans source code still looks for this option :D
I have done some initial tests and it really works as expected for NetBeans 6.9 and I hope it can help you as it will help me a lot.