My backup of SPS DB (Farm selected as content) is much smaller (5 GB) than my SPS DOC (All Versions) backup (150 GB). All backups seem to complete succesfully. Does this indicate a problem, or could there be an explanation for this?
Do you have the option from step 6 configured: http://documentation.commvault.com/commvault/v11/article?p=17841.htm
My guess is that you do not, and are backing up the actual SQL databases in a different way (which is fine) but would explain the difference in size. The SharePoint DB backup will secure web applications (IIS metadata and configuration, but not the content databases by default), service applications, and configuration details. The actual contents is in the content databases on the SQL back end which is what your SharePoint doc backup is securing.