@Nishikant,
yes, when testing on a limited-resource VM, I shut down anything I don't need.
Still, with limited resources, don't expect awesome performance. If you are using YARN, that spins up containers that will require memory as well.
If you have Cloudera Manager installed, it is what you use to start and stop all hadoop roles.
You may also need to configure heap space in Cloudera Manager to reduce the heap to ensure you don't overcommit.
