Just moved cacti DB and RRD files to a new server . After moving RRD from 32bit OS to 64bit OS you will meet
"ERROR: This RRD was created on another architecture" in your http error logs and you will not see your historic graphs.
You should dump your rrd files on 32bit OS and transfer them to your new server(64bit).. Then you should restore your xmls..
on 32bit OS
for i in `find -name "*.rrd"`; do path_to_rrdtool dump $i > $i.xml; done
on 64bit OS
for i in `find -name "*.xml"`; do path_to_rrdtool restore $i `echo $i |sed s/.xml//g`; done