Follow-up from https://discussions.apple.com/message/13337119#13337119

Follow-up from https://discussions.apple.com/thread/2805056?answerId=13337119022#13337119022

(question about Time Machine in Snow Leopard's time).

15 months later, here I am, back again with yet another horror story.

Mac OS X 10.7.4. Since the last problem, I kept using both the disk utility and Time Machine. The process for using Time Machine is still the same as described in April 2011. That is, the Mac's two users are encrypted using the old Filevault (which is, as far as function goes, a better solution than the new one that encrypts the whole system disk - if only because it allows to encrypt the users' data while having a non encrypted admin account from which maintenance can be done by a person that does not need to access confidential data). Time Machine saves are done manually from this admin non encrypted account while the two users are logged out and the modem is powered off.

Recently, because the Time-Machine Firewire disk was becoming a bit full, I erased it (after doing two separate full disk backups using disk utility and testing that I could reboot from each of these two backups). I then did a full Time Machine save of the disk. Since then, only two incremental Time Machine saves were done, using the above process.

Then a minor disaster struck. An erroneous command deleted a very big lot of important user files (and the wastebasket was emptied before it was realised that these files had been lost). OK. That's why backups are done, and the last of the two incremental Time Machine saves had been done in the morning. So, no reason to panic.

I powered up the Firewire disk and opened the encrypted user directory saved that very morning on the Time Machine disk. The whole directory structure was present and visible. Only, ABOUT EIGHTY PERCENT OF THE USER DATA FILES WERE CORRUPT ONE WAY OR ANOTHER AND UNUSABLE!!!!!

Given this, the surprising thing is that the remaining twenty percent of the data files were OK...

I had to use one of the backups done with the disk utility to recover the other lost files. Meaning a little over a week worth of data files were lost...

Since I started using Time Machine, I did two sets of tests, which were OK and produced bootable and usable restore but did not include incremental saves. And in the two occasions where I had to use the incremental backups to recover lost data, I was presented with corrupted files or disks!!! Good record, isn't it?

I previously wrote that Time Machine was NOT a backup utility but, at best, a fancy copy utility, because it did not check the integrity of the saved data. Today I must reckon that it isn't even a copy utility, but a death trap!

BACKUPS INTEGRITY IS THE SINGLE MOST IMPORTANT FEATURE ON A COMPUTER. That Apple is advertising such a trash as Time Machine as a backup utility is simply criminal! And it may cause unlimited damage to whoever is mad or gullible enough to trust her/his data to it...