Redhat/Debian Update Support

Preventing Kernel Updates in Linux
Ubuntu/Debian
http://www.howtogeek.com/howto/10606/how-to-hide-kernel-updates-in-ubuntu/

RedHat
http://www.howtogeek.com/50898/how-to-prevent-yum-from-updating-the-kernel/

List Available updates in Linux
Debian
aptitude search '?upgradable'

Redhat
sudo yum list updates
http://yum.baseurl.org/wiki/YumCommands


Automatic Security Updates
Ubuntu
https://help.ubuntu.com/community/AutomaticSecurityUpdates


Download only packages without installing
Redhat
yum install -y yum-downloadonly
yum install httpd -y --downloadonly --downloaddir=/my/download/dir/
http://www.cyberciti.biz/faq/yum-downloadonly-plugin/

Ubuntu
apt-get -d, --download-only ...