[Xymon] Create historical data

Hi all experts!

I have a couple of gauges in my system that is sending data to xymon.

That is fine. It is plotting nicely on graphs for the day, 2 days, 48 days and two years.

But It only plots data from a certain date (the start date)

I would like to dig up the data from our database and re-create the historical data.

How can that be done ?

Any tips or ideas ?!

I assume I need to use some lowlevel formatting with the rrd tool – but how ?

I just need some tips&trix so I can recreate two values for a specific date into rrd database.

Anyone knows ?

//Björn