check-new-release process eating up resources on Ubuntu server 13.04
Try doing
apt-get remove ubuntu-release-upgrader-core
The script that you're seeing running is /usr/lib/ubuntu-release-upgrader/check-new-release, and removing the above package will remove that script completely.
A description of this package is:
ubuntu-release-upgrader-core - manage release upgrades
In the file /etc/update-manager/release-upgrades change Prompt=normal to Prompt=never.
You can also do this through the GUI, but that may not be appropriate for a virtual server.
You can do a manual check for a new release with do-release-upgrade