Hi,
I had the same issue and I was able to fix it by
logging into the vCenter console and modifying the passwd file
~# vi /etc/passwd
and change the appliancesh to /bin/bash
root:x:0:0:root:/root:/bin/bash
Also make sure that ssh access for root is enabled from /etc/ssh/sshd_config
Regards,
Naveen
Technical Support Engineer
VMware, INC