On the old one, SME9, but you're out of luck,
http://viewvc.koozali.org/smecontribs/rpms/smeserver-migratehelper/contribs10/migratehelper.sh is unreachable for the moment.
"You must first create the mount point and mount your external disk already formatted and with sufficient place to receive the archive:
mkdir /mnt/backup
mount /dev/mydisk /mnt/backup"
"Then run the script."
On SME11: "First step will be to simply use the console restore with the obtained smeserver.tgz. We expect you handle the transfer either using a USB disk, or ..."
https://wiki.koozali.org/Migratehelper"Second use the configuration console to fix any changes needed on network card or IP, domain name...
Third you can use the saved list of rpm to try to install your contribs and other missing things
Fourth, you can start a rsync for the missing bits"