su - vrack
cd /home/vrack/.ssh
cp -p known_hosts known_hosts-bak
Example:
#172.30.0.33 ssh-rsa AAAAB3NzaC1yc2EAAAADAQABAAABAQDgXx7pKj4D63b6opRgddgddOpKQ78Vnxp9BmQzDbhYcIN5hmdYYCrIzF3OTs7D8hDvRXds0JjRH6fj05KuL9JZAgEELxHvIiQGvJ+A918NQoNpmW6dDSA07IaA2VZ442lyB9+BSXPnuuymFQ+fGtKVXArq3Qf+/MMlpBUKuywqQgOVQG52nLr4O79/5qdKVg/IpEqfya1hjOIGwnh6yLx5x33RxITii5gd5t9XrulL+MkE/ZS6tBvSQ59PCpwHCpIezh0bmgAxUs4FldbxxCOLI+6ynncAoxWq40my2QQqiZXNdQviCSfBR7N0DOuztbaSiWdggdgddJHiuSqo2QcRpx5ZevPmreIrfgdNIyZ
#psc-2.vcf.vxrack.local ssh-rsa AAAAB3NzaC1yc2EAAAADAQABAAABAQDgXx7pKj4D63b6opRgddgddOpKQ78Vnxp9BmQzDbhYcIN5hmdYYCrIzF3OTs7D8hDvRXds0JjRH6fj05KuL9JZAgEELxHvIiQGvJ+A918NQoNpmW6dDSA07IaA2VZ442lyB9+BSXPnuuymFQ+fGtKVXArq3Qf+/MMlpBUKuywqQgOVQG52nLr4O79/5qdKVg/IpEqfya1hjOIGwnh6yLx5x33RxITii5gd5t9XrulL+MkE/ZS6tBvSQ59PCpwHCpIezh0bmgAxUs4FldbxxCOLI+6ynncAoxWq40my2QQqiZXNdQviCSfBR7N0DOuztbaSiWdggdgddJHiuSqo2QcRpx5ZevPmreIrfgdNIyZ