As long as your laptop is running a supported operating system (RHEL or
CentOS 5/6, SLES 11, Ubuntu 12.04 / 14.04, Debian 7), you can just follow
this guide:
http://www.cloudera.com/content/cloudera/en/documentation/core/latest/topics/cdh_qs.htmlOtherwise, you will first need to install one of these systems in a VM. You
should be able to complete that Hadoop example in a VM with that much RAM,
but be aware that you would have some trouble running the rest of the stack
that is not core Hadoop: the QuickStart VM has everything pre-installed and
configured, but requires 4GB of RAM for the VM itself.