Calculating Bandwidth OUT

We are thinking of moving from a “dedicated server” product to a GoGrid cloud server. For Cloud machines, everything is pro-rated, so to get some estimate I need to analyze the bandwidth of our current box.

For the Cloud server instance, we would only pay for bandwidth out. So I need a way to analyze bandwidth out for each virtual server/website – well actually the whole CentOS box.

VirtualMin -->System Statistics --> has a check box for “Network Traffic Sent”

If I click for a month I get a interesting graphs and I can download raw data in the form of a delimited file:

2014-06-08 14:55:01,0.82,180.90
2014-06-08 15:35:03,0.56,106.67
2014-06-08 16:15:06,0.93,66.93
2014-06-08 16:55:08,1.16,87.66

So, questions:

  1. is this “network traffic out” the same as “bandwidth out” I presume so… but since Webmin–>Networking–>Bandwidth is also available (but off by default) it made me wonder if these stats in VirtualMin are something different.

  2. assuming the answer to 1) above is “yes” then which of these values are the amount of traffic? I presume the last one… then what is the 3rd column?

Date Time ?? ?? # bytes out here?
2014-06-08 14:55:01, 0.82, 180.90

If the last number is bytes out, presumably you can download the raw data for a month, sum the last column divide by 1024/1024 to get MB of bandwidth out… Looks simple enough.

Can anyone confirm?


When Virtualmin provides bandwidth information, it’s specific to a few services – websites, FTP, and email.

It doesn’t count each and every packet. Instead, it reads log files for those three services, and totals up the bandwidth that they used.

Typically, that accounts for most bandwidth – but it’s not all bandwidth.

Using Webmin --> Networking --> Bandwidth is a different kind of bandwidth accounting – that’s packet based accounting. That will account for each and every packet that leaves your system, but it uses more resources to run.

In general, the majority of your bandwidth usage is going to be outgoing bandwidth.

So if you look in System Settings -> Bandwidth Monitoring -> Usage Graph, that will be fairly accurate. You can see totals at the bottom.

You can use the System Statistics to review bandwidth monitoring too, and the stats there are obtained the same way, but that’s designed to show bandwidth usage over time. It shows it in “Network traffic sent in kB per second”.

If your goal is to get an estimate of bandwidth usage for a full month, you’d probably want to review the bandwidth monitoring usage graph.


“So if you look in System Settings -> Bandwidth Monitoring -> Usage Graph, that will be fairly accurate. You can see totals at the bottom.”

duh! I missed that one… thanks… exactly what I need for working out a business plan I don’t need anything super accurate… within 20GB plus or minus, is good enough for cost estimating. So this graph is perfect!


Oh Wait… One Site shows zero Bandwidth. But this is impossible, it is our international org social networking site and is very active, though only by small group of registers member and students.

Meanwhile other sides like “” which we host for a non-profit here on the island… get almost no traffic other than bots but shows at least 10.62 MB of usage. while our other big site shows 0. That site requires a log in to see anything at all, but VirtualMin should be able to see the logs. Any ideas why it would show usage 0 bytes, when we know for sure it is quite active?