If you have a Gentoo machine running on Linode, take care to note that the eudev => udev changeover requires some manual intervention before the next reboot.
You will need to DISABLE the network autoconfiguration option for the VM, and edit /etc/conf.d/net to specify the new, 'predictable' network interface name. This is because Linode's network autoconfigurator is hard-coded to generate a configuration using the traditional style of network interface names, eg. eth0 Alternatively, you can make whatever changes are required to have the system enumerate the network interfaces with the old style names. If you do neither of those things, you will need to use the rescue console in order to log into the machine and fix your network configuration, as the system will not be able to bring up the network on its next boot. Ask me how I learned this.
