Why I got 'unable to resolve host' when I do 'sudo'? [duplicate]

Whenever I do 'sudo' I get an error saying 'sudo: unable to resolve host HP-Pavilion'. I recently change my hostname to "HP-Pavilion". I wonder if I screw up something.

$ sudo mkdir SourceCodePro
sudo: unable to resolve host HP-Pavilion
[sudo] password for mike:

Thank you for your help.

You changed the host name to HP-Pavilion, but it's not in the file /etc/hosts. So try to add the name to /etc/hosts file and also don't forget to add it to /etc/hostname file .

Your /etc/hosts and /etc/hostname files will look like this,

$ cat /etc/hostname
HP-Pavilion
$ cat /etc/hosts
127.0.0.1   localhost
127.0.1.1   HP-Pavilion

Restart your pc to make changes work.