Hacker’s Diary

I usually set hostname during Linux installation, but many people don’t. Then without a knowledge it could take some time to change it correctly.

Doing so:

will only change hostname temporary, after system reboot it will change back to what it was specified during installation.

So the right (my) way of changing hostname:

• Some linux systems keep hostname record in /etc/sysconfig/network
  

  HOSTNAME=localhost.localdomain

• Debian systems /etc/hostname

  localhost.localdomain

• Additionally hostname is kept in /etc/sysctl.conf

  kernel.domainname = localdomain (usually uncommented)

  kernel.hostname = localhost

And at the end, don’t forget to add hostname to /etc/hosts file like this:

127.0.0.1       newhostname.localdomain       newhostname

or

127.0.0.1       newhostname

Otherwise services like Apache, Squid and many others won’t run correctly or won’t run at all if they can’t resolve the hostname either by hosts file or DNS server.