Hi Greg,
What revision of HANA were you upgrading from? And do you find any update log file in /var/tmp?
Regarding your question about ./HDB stop and ./HDB start - to do the update, you need to be logged on as root. The HANA startup and shutdown commands are executed as user <SID>adm (in our case hdbadm). So switch to user hdbadm by typing su - hdbadm. That should take you into directory /usr/sap/HDB/HDB00. From there you should be able to do ./HDB stop and then ./HDB start
hope this helps
--juergen