A co-worker has been working on a reporting tool to allow a Mac user to get reports from Time Machine whenever there’s a failure in the backup. Failure messages occasionally come up when Time Machine runs, but it never says what folder, what file or really what kind of failure occured. Which is not what you want if you are absolutely depending on the data being recoverable via Time Machine. It’s not bulletproof and it will lull you into complacency once you have it up and running. I tend to agree that a belt and suspenders approach is best. I’ve read countless articles saying Disk Clones are the best, and on the other side, Incremental Backups are most accurate (in terms of having the latest version of a file) and more efficient with disk space (no need to duplicate the system folder again right?) With the cost of Western Digital My Books dropping all the time, you could purchase two separate USB2 Lifebooks, use a disk cloning utility for one drive, Time Machine for the other. Then you would have a bullet proof backup scheme. One reader commented in this article that off-site backup is necessary as well, so include that as the third leg of your backup triad.
Since errors and failure can happen in any backup system, we recommend that if you have the available resources (namely, spare external hard drives) that you set up dual, independent backups, and, in doing so, take advantage of more than one way of backing up your system. This will prevent any errors in a backup system from propagating to subsequent backups.
One strongly recommended solution that we advocate is to have both a snapshot-based system such as Time Machine in addition to a bootable clone system as well using a software package such as SuperDuper or Carbon Copy Cloner. Doing this will ensure you can both boot and access your most recently changed files in the event of either data loss or hardware failure.