The root partition will host the operating system files. Fresh CentOS 6 install with basic server packages + OpenVZ kernel can occupy up to approximately 2 GB of disk space, so 4 GB is a good minimal size of the root partition. If you have plenty of drive space and think you may add additional software to the Node such as monitoring software then consider using more. Historically, the recommended size of the swap partition has been two times the size of physical RAM installed. Now, with minimum server RAM often above 2GB a more reasonable specification would be RAM + 2GB if RAM is above 2GB and HD space is limited.

=== Finishing OS Installation ===