Recently we changed the backup Server for our vCenter. The backup job over SCP worked for years on the old Server, but on the new one I was not able to configure the backup-schedule. I got always a timeout on the vCenter Server Appliance Management Web-GUI and I had to restart it with:

service-control --restart applmgmt

To get it working again without rebooting the whole vCenter Appliance.

After a few hours of debugging, I saw a process named sshpass which was hanging.
sshpass tries to find "Password:" in the prompt and sends then the password.

Now the problem was, the old Server had a prompt like:

Password:

And the new one had:

Password for username@servername:

So sshpass was not able to find "Password:" and timed out.

As both our servers are BSD, I had to fix the sshd config on the new Server for PAM in /etc/pam.d/sshd with adding of "authtok_prompt=Password:" and then restart sshd.

#auth required pam_unix.so no_warn try_first_pass
auth required pam_unix.so no_warn try_first_pass authtok_prompt=Password:

With this setting, the prompt changes from "Password for ...." to "Password:".
And the backup-schedule works again :-)