This script you run on the source host from the same directory where all those rrd files are there. I found this very helpful while migrating between Linux and Solaris.
set all_files=`echo *.rrd`
foreach file ( $all_files )
set base = `basename $file .rrd`
/bin/rrdtool dump $file > /tmp/new1/$base.xml
The do a `tar` with `gzip` as that will save lots of space and time while transferring data between machines.
And on the destination machine you uncompress and untar the file to an empty directory.
set all_files=`echo *.xml`
foreach file ($all_files)
set base = `basename $file .xml`
/opt/local/bin/rrdtool restore $file /opt/local/htdocs/cacti/rra/$base.rrd
Hope this helps.