If your site is VHOSTed, then you can access your site's own log file by:

1. ssh to your VHOST with ssh {LOGNAME}@{VHOSTDOMAIN} with your normal LOGNAME and password. (this actually logs you into the 'norge' server with a few environment variables set)
2. Change to your html folder by using the $VHOST environment variable, e.g. cd $VHOST

ex:

$ ssh peteyboy@irulecomputers.com
… (login stuff)
Welcome to the dedicated VHOST membership server

log files:     /var/log/nginx
html files:    /vhost/www 

The $VHOST environment variable will provide the full path to your site.
$ cd $VHOST
$pwd
/vhost/www/nz/p/peteyboy
$

This folder will contain subfolders, each for your different VHOSTS. In those folders, place all the web files for your website, as you would in ~/html for your site on the cluster, ex:

$ls
irulecomputers.com/
$

your log files are /var/log/nginx/{VHOSTDOMAIN} and /var/log/nginx/{VHOSTDOMAIN}.err