how to know snapshot internal structure?

Hi folks,

a snapshot on an existing lv keeps all the delta right? i guess snapshot will keep a in memory look up table for this. but during system reboot, this information should have a on-disk copy as well. is there any doc or hint about the on disk location and structure? i guess it is part of the snapshot area.

open the lv will read all new data and all unchanged data. open the snapshot will read all old data. so is there any quick way to know what exactly the delta are?

thanks a lot.

ming