Newbie needs help with ERROR: could not write to file "base/16390/2682": No space left on device

I am trying to following the instructions at URL below to try to create a
database called web_database required for phpPgAdmin. When I try to do this
I get the following error:

template1=# create database web_database owner web_user;
ERROR: could not write to file "base/16390/2682": No space left on device
template1=# exit
template1-# \q

Any ideas what may be causing this to happen?

Your help would be greatly appreciated.

- Andrew

http://resources.angelosystems.com/postgresql.html