postgres ssh-copy-id: ERROR: No identities found

I'm working on hot_standby with postgresql on centos. One thing I got stuck on being a noob at linux was how to create ssh keys for the postgres account. I was following the 3dtin blog on postgresql hot_standby and got stuck at the following point; 
su - postgres 
ssh-copy-id 
ssh-copy-id: ERROR: No identities found 

Ok, remove that pesky selinux. I believe that's at fault. Set SELINUX in /etc/sysconfig/selinux to disabled. 
su - postgres; pwd should be /var/lib/pgsql 
mkdir .ssh 
ssh-keygen (hit defaults) 
ssh-copy-id -i ~./ssh/id_rsa.pub 
check with ssh So if you do that on the pg_master and drop the key on the pg_slave, you should then repeat the other way (as the 3dtin blog says).