I am trying to establish passwordless connectivity between server A and server B, but unsuccessfuly, because I beleive two issues.
the first one is that on both servers, it is not possible to use root to login, it only allows to connect using a user (any) them su - root , which in turns I am able to login. So I thought the PermitRootLogin value was set to NO, but there is no file /etc/ssh/sshd_config on the server.
The second issue is that even if I use the procedure in SSH Passwordless Login Using SSH Keygen in 5 Easy Steps, is not allowing me to login with user root or any other user.
My ultimate goal is to use the tape device on server B to backup root file system of server A, using the following command: ufsdump 0ucf serverB:/dev/rmt/0 / .
Initially I created a file /etc/.rhosts on server B, and inserted hostname and user, but I was not able to use the ufsdump command.
Sounds like an RBAC problem - create a non-root user that can login over network with the necessary permissions to run disk maintenance (backup, etc)? Add ssh keys for the user. Put your local ssh keys in the .ssh directory over there.
Create a script in the user's directory to do what you need.
ssh user@hostname 'script.shl [parameters for the script]'
PS: you can use tar over the network to create local tarballs from your remote disk.
ssh -e user@remote 'path/to/script.shl' | tar cf local.tar -