Linux – How to change the server’s host name

You want to add its init script to the appropriate run level. The init script is typically /etc/init.d/apache2 where you could manually run /etc/init.d/apache2 start to start it.

On Gentoo you would write:

rc-update add apache2 default

On Ubuntu/Debian this works:

sudo update-rc.d apache2 defaults

On Red Hat Linux/Fedora/CentOS a little googling shows this:

chkconfig --add httpd

It varies a little bit from distribution to distribution , but the idea is usually the same. Basically, all these commands make a symbolic link from /etc/init.d/ to the appropriate run-level folder in /etc/.

The Ubuntu kernel is not the same as the upstream kernel, although the version numbers may be similiar. You can read about the Ubuntu Kernel in the Ubuntu Wiki which answers your first and your fourth question:

Beta-2 includes the 3.2.0-20.33 Ubuntu kernel which is based on the v3.2.12 upstream stable Linux kernel.

The Ubuntu Kernel FAQ describes the version numbering as follows:

Given a version like 2.6.35-6.9-generic this can be broken into four parts as below:

<base kernel version>-<ABI number>.<upload number>-<flavour> The base kernel version represents the mainline version on which the Ubuntu kernel is based. The ABI number represents significant changes in the kernel Application Binary Interface. The upload number is a monotonically increasing counter for each upload of this base version. The flavour indicates which kernel configuration variant this is

You can also check the Ubuntu to Mainline kernel version mapping for more information on ubuntu kernel versions vs upstream kernel versions.