When ntop is restarted the ntop counter gets reset and all stats are gone

From ntop FAQ

Q1(a). Can I store data in a SQL database?

Q1(b). When ntop stops I lose all my data. Why?

Q1(c). Why doesn't the -S option work?

A. ntop used to optionally store some data in a SQL database. The code was broken, difficult to maintain, etc. and was removed. A LONG TIME AGO. If you are reading about this in 'some' documentation - update.

Current ntop is 3.1, which is the only version we support.

There are scripts that various users have offered to take the data dump and insert it into a SQL database. Search the back traffic on the mailing list for them.

Yes, ntop uses memory based structures to hold usage data and they are lost when you reset or restart ntop.

Persistent storage is in the RRD databases - there's a paper @ SourceForge that explains them.

There was another option for some persistence - it was -S - look in FAQarchive for an article about it, "What was the -S option?".

I was advised by the ntop community to update to the SVN version of ntop, and this did indeed start populating the graphs without configuring things differently.

However, I have found that after collecting data for a few weeks, I am not seeing useful results. I have read that there are certain limitations with the netflow data from ASAs which may result in this. I think for better analysis I am probably looking at a different collection mechanism for data, and the lack of current and clear documentation for NTOP means I am probably looking elsewhere for collating and interpreting the data too. Back to the drawing board!