How often do Time Machine files corrupt?

[duggram]

In today's Wall Street Journal there is a review of SL. The reviewer had problems with TM. Apple told him that his TM file had been corrupt for 2 months!!

How often does this happen?

Are there any good strategies for dealing with this potential problem? Should a user keep two TM external hard drives?

 

[BobZune]

There is no good way to tell. There are anecdotes of TM related restore/corruption issues on occasion, and some are user error and some may be due to other reasons (including possibly TM software issues). Some people swear by TM and some don't have a good opinion. I personally use it and have had occasion to restore from it a few times for various reasons, with no problem; but my personal opinion (everyone has at least one) is that it is "very good" but not yet "excellent" in terms of reliability.

If you want a second backup, you may want to consider a bootable backup with SuperDuper or Carbon Copy Cloner. Those are easily verified by booting from them.

If you are even more careful, you may want to consider DiskWarrior (or equivalent programs). Use every few months and repair/rebuild as you see fit.