Fuse ESB 7.5 : karaf hangs

I have a default fuse ESB 7.1 (zip file) installed on centos VM.

I noticed that when i use karaf console, it for the most of the time

hangs and i have to

kill the process using kill -9 to get rid of it.

And every time it hangs, it creates a dump file..

Do you know what should be done to prevent this ?

It s a memory problem, how to change this ?

Thnx