You don't have permission to access / on this server.

没有权限访问根目录

应该是配置文件写错了， 写成了这样？ Directory "/"

刚好也遇到了这个问题，出现这个问题的原因有很多，解决这个问题的方法根据你apache的版本不同，解决方法也不同，如果你是最近安装的话，那么apache的版本应该是2.4的。它配置虚拟目录跟2.2不同。
你仔细看看这篇文章： http://linux.cn/article-3164-1.html
这个是在apache默认目录设置的，如果虚拟目录不是建在/var/www的话，那么要如下这样设置：

 ServerName 127.0.0.1:80
<Directory /home/hehongwei/wwwroot/>
        Options Indexes FollowSymLinks
        AllowOverride None
        Require all granted
</Directory>
<VirtualHost *:80>
        # The ServerName directive sets the request scheme, hostname and port that
        # the server uses to identify itself. This is used when creating
        # redirection URLs. In the context of virtual hosts, the ServerName
        # specifies what hostname must appear in the request's Host: header to
        # match this virtual host. For the default virtual host (this file) this
        # value is not decisive as it is used as a last resort host regardless.
        # However, you must set it for any further virtual host explicitly.
        #ServerName www.example.com
        ServerName unixmen1.local
        ServerAlias www.unixmen1.local
        ServerAdmin webmaster@localhost
        DocumentRoot /home/hehongwei/wwwroot


        # Available loglevels: trace8, ..., trace1, debug, info, notice, warn,
        # error, crit, alert, emerg.
        # It is also possible to configure the loglevel for particular
        # modules, e.g.
        #LogLevel info ssl:warn

        ErrorLog ${APACHE_LOG_DIR}/error.log
        CustomLog ${APACHE_LOG_DIR}/access.log combined


        # For most configuration files from conf-available/, which are
        # enabled or disabled at a global level, it is possible to
        # include a line for only one particular virtual host. For example the
        # following line enables the CGI configuration for this host only
        # after it has been globally disabled with "a2disconf".
        #Include conf-available/serve-cgi-bin.conf
</VirtualHost>