sudo a2enmod rewrite
sudo service apache2 restart

octopus@pc3:~$ sudo a2enmod rewrite
[sudo] password for octopus:
Enabling module rewrite.
Run '/etc/init.d/apache2 restart' to activate new configuration!
octopus@pc3:~$ sudo service apache2 restart
 * Restarting web server apache2                                                apache2: Could not reliably determine the server's fully qualified domain name, using 127.0.1.1 for ServerName
 ... waiting apache2: Could not reliably determine the server's fully qualified domain name, using 127.0.1.1 for ServerName
                                                                         [ OK ]
octopus@pc3:~$

这是ubuntu下启用重写模块的最简单方法