• From a quick Google to http://www.jdmz.net/ssh/, the command structure is like this:

$ rsync -avz -e "ssh -i /home/thisuser/cron/thishost-rsync-key" remoteuser@remotehost:/remote/dir /this/dir/

• Or, with your ~/.ssh/config setup for your identity file

Host remotehost
User remoteuser
Compression yes
Protocol 2
RSAAuthentication yes
StrictHostKeyChecking no
ForwardAgent yes
ForwardX11 yes
IdentityFile /home/localuser/.ssh/id_remotehost_dsa

• then you can do this

rsync -e ssh -avz --delete /home/folder1/ server02:/home/folder

• Setup ssh keys backup with unison or rsync

cd /bin
wget http://www.cis.upenn.edu/~bcpierce/unison/download/stable/latest/unison.linux-textui
mv unison.linux-textui unison
chmod +x unison

Then run this example at the first cluster to sync /var/www/html/ directories on both:

unison /var/www/html ssh://server02//var/www/html -batch

You can put as many of these as you like in the crontab (crontab -e), 1st run is slow, rest are fast.

http://www.microwerks.net/~hugo/ - mondo, disaster recovery | http://mkcdrec.ota.be/ - mkcdrec, make cdrom recovery

gentoo recommendation ssh keys and rdiff - also see flexbackup in the doc adv Bash script example to include dates in file names