Ceph » Orchestrator

Currently:

master:~ # ceph orch host add mgr0 192.168.121.230                                                                                                              
Error ENOENT: Failed to connect to mgr0 (192.168.121.230).
Check that the host is reachable and accepts connections using the cephadm SSH key

you may want to run:
> ceph cephadm get-ssh-config > ssh_config
> ceph config-key get mgr/cephadm/ssh_identity_key > key
> ssh -F ssh_config -i key root@mgr0

What actually needs to be done:

master:~ # ceph config-key get mgr/cephadm/ssh_identity_pub > key.pub
master:~ # ssh-copy-id -i "key.pub" root@mgr0

What the message should look like in the end:

master:~ # ceph orch host add mgr0 192.168.121.230                                                                                                              
Error ENOENT: Failed to connect to mgr0 (192.168.121.230).
Check that the host is reachable and accepts connections using the cephadm SSH key

you may want to add the SSH key to the host:
> ceph config-key get mgr/cephadm/ssh_identity_pub > ~/cephadm_ssh_key.pub
> ssh-copy-id -i ~/cephadm_ssh_key.pub root@mgr0

you may want to check that everything works, before rerunning the command:
> ceph cephadm get-ssh-config > ssh_config
> ceph config-key get mgr/cephadm/ssh_identity_key > ~/cephadm_ssh_key
> ssh -F ssh_config -i ~/cephadm_ssh_key root@mgr0