Different methods of use on an OVH server
The Linux kernel is the part of your dedicated server, which is the link between the hardware of your server and your OS (Linux). It's a programm, loaded in memory at the start of your machine and it allows you to run your dedicated server. The kernel is fully independent from the system installed on your server (RedHat, Debian or Fedora). Its development is completely independent and as all programs, it is regularly up dated. For more details, see the official site of the kernel. OVH proposes you 2 methods to manage and update the kernel on your server: the Netboot and hard disk setup.
The Netboot is a technology used at OVH and that enables you to load Linux kernel on your server from the network. As soon as a new kernel is out, OVH compiles the new version and make it available on the network for all dedicated servers hosted at OVH. You just have to configure your server in order it to start on this new kernel and to reboot it. At the next start, you server will then directly load the new kernel. This is a very simple and very fast technique to maintain the kernel up to date on your server.
Note: With regards of Total Security, the Netboot is used for maintaining your server kernel up to date
For different reasons of choice or technical capacities, you may be led not to use the Netboot. In that case, OVH makes also available pre-compiled pictures of the kernel latest version. Then, you just have to install the image that corresponds to your configuration on your hard disk and then configure your server in order it to start the kernel on its hard disk. With this technique, you will have to make sure that the kernel is always up to date on your hard disk.
For more details about this use, you may consult this manual: KernelInstall.