Where is the RRD stored when on the pool

[Knowltey]

So if I have the system dataset set up to be saved on the pool, and the Reporting Database box on that page set up as well, where on the actual pool is it saved, because I can't seem to find it anywhere?

Reason I ask is because when I did the latest update it seems to have started a new RRD. However if I revert to the previous bootset from before the application of the update it's still there, so it seems the data still exists somewhere, I just can't seem to locate it...

Also, if I locate is there a way to tell it to use the old database that has the year of data or do I have to do it like I did in the past with just copying the contents into the newly created database?