CentOS

[quote]The OpenVZ Project follows the RHEL kernels closely and provides updates in a somewhat timely fashion after updated Red Hat (and CentOS) kernels are released. ....
[b]Please note though that the OpenVZ kernel is less modular[/b] than the stock Red Hat / CentOS kernels with some hardware support being compiled in.[/quote]

Just that - drivers are compiled into the kernel, rather than being loaded as modules.

Try a google on [url=http://www.google.com/search?q=linux+kernel+loadable+modules&ie=utf-8&oe=utf-8&aq=t&rls=org.mozilla:en-US:official&client=firefox-a&safe=active]linux kernel loadable modules[/url] for more.