When starting karaf with arguments meant for jvm they are ignored

When starting karaf with f.ex.
/start -Xmx2G -XX:MaxPermSize=256M -XX:+PrintGCDetails -Xloggc:gc.log

the flags are ignored. You can see them when running ps aux but they dont get through to the jvm so it runs without them. It's possible to set the memory flags in setenv script but the others are ignored silently.