PMSS:Bandwidth monitoring
From Pulsed Media Wiki
Bandwidth monitoring is automatically setup - no limits or shaping, simple monitoring. Stats are collected in files and sent to management server every several minutes.
You can view user traffic usage with showTraffic in console. File is in path so works anywhere. This displays bandwidth and traffic usage per user for the past week, this includes SFTP, FTP, SCP and Torrent traffic.
To view complete server usage vnstat has been installed, ie. vnstat -d will display per day statistics and vnstat -m will display per month statistics.