Is the built in Windows server backup enough?
I am asking this because one time I had a failure. The DC died from a bad update and I tried to restore from a backup and it failed. Over and over again, eventually I realized the external drive I was backing up to was going bad. I was able to retrieve the files, re-install sbs 2008, setup the domain and move the files back. This was a real pain, especially getting all of the mailboxes back to where they needed to be. Also some of the mailboxes were corrupt. I actually never fully recovered SharePoint, that was the only thing I really lost.
So is there a better way to backup the system state, all of the redirected files, exchange and sharepoint. Every single backup claimed it completed successfully and there were 200+ available points to recover from but none worked. How do I detect this failure before it happens in the future and replace the external?
Because of this, I am paranoid and run a full backup before I run any system updates.