PingPlotter save files always include what is in memory at the time of the save. Depending on your trace interval, it may not be a good idea to have a month's worth of data in memory at once, which makes doing a month-in-a-file difficult.

In theory, it's possible, though. The number of save files is controlled by the file name you pick. If you use $year-$month-$day in your file name, you'll get a new file every day. If you use $year-$month, each save will overwrite the previous file until you hit a new month, and then each save will overwrite that month's file till the end of the month. If you have enough memory to hold a month's worth, this should work for you.

There are some other options here, though. First, we have a knowledge base article on long term monitoring, saving of data, and memory use:

http://www.nessoft.com/kb/44

If you're using PingPlotter Pro, you can combine multiple save files into one by multi-selecting them when you load. So if you have a new file every day, you can multi-select a month's worth and load them all into memory (as long as you have enough memory). We've successfully done this with about a year of data at 1 sample every 2.5 seconds, but that's on a 2 gig of ram computer (that's 12 million samples - at 50 bytes per sample for a 20 hop route, that's 600 megs of ram, and we have two copies of this in memory for some portions of the combination process).

Hopefully, this gives you something to think about. Feel free to follow up with any other questions about this topic.

- Pete