Carbon Copy Cloner corrupts Time Machine?

You might want to contact their support - he is really good at answering.

http://www.bombich.com/ccc_support.html

i don't use Time machine, so I can only guess and my guess would be that two different backup programs running at the same time could easily cause a problem.

I'm going to see if I can get our TM guru's attention....

I responded to your CCC post and think the tech's smoking too much cloudy stuff. There's no connection between a CCC clone and a TM backup, even if both are going to the same ext HD volume. Since you never described what you did, I really guessing.

I was passed to a Senior Technician. When he learned that I also use Carbon Copy Cloner (currently version 3.4.4) he told me that Apple has been getting a lot of complaints that CCC corrupts Time Machine backup files. When I asked further, he advised that this is a relatively recent development, over the past several iterations of System X.

I would have to concur with baltwo's assessment of that tech. There's no problem with CCC and Time Machine. I've been using both to maintain several separate backups for years, and have never had a problem as a result. How are you using CCC?

Unfortunately, it is a simple fact of life that backups can become corrupt, and often that is not discovered until the very moment you need the backup the most. That's one big reason to keep multiple backups, made with two different backup programs.

CCC goes to great lengths to avoid all Time Machine business for file-level copies. If you were to clone any other volume to a Time Machine volume, the Backups.backupdb folder is explicitly protected from any modification whatsoever. CCC also won't copy the contents of a Backups.backupdb folder if you were to clone the Time Machine volume to some other volume -- I explain why that is here in the documentation:

Cloning a Time Machine backup

The only scenario in which CCC will copy a Time Machine volume is when you ask for a block-level copy, and in that case, the entire volume -- bit-for-bit -- is copied precisely to the destination volume. To this day, I've never received a single report of potential corruption of Time Machine "files". I've received several reports where people came to me with corrupted Time Machine backups and they hoped that CCC could help them get out of the mess, but never a suggestion that CCC was involved in the corruption. Given the lengths I go to to avoid modifying TM backups, I certainly wouldn't expect there to be a correlation.

I'll follow up with AppleCare on these other purported complaints to see if there's any meat to that. If there's a real issue here, I'll deal with it immediately, but I think it's more likely that the corruption of your TM backup (or the restore mechanism -- it isn't clear which is broken) is unrelated to your use of CCC.

Mike

Mike Bombich

Bombich Software, Inc.

http://help.bombich.com

...we found that the backup files were corrupted.

How did you find that?

Randy Knowles wrote:

. . .

he told me that Apple has been getting a lot of complaints that CCC corrupts Time Machine backup files. When I asked further, he advised that this is a relatively recent development, over the past several iterations of System X.

I also think this is malarky.

I use CCC and TM, as do many people, have spent lots of times on these forums, and have never heard of it. In my setup, my Mac wakes up early in the morning to update my CCC clone, and a TM backup usually runs at the same time.

The way CCC finds what's changed and needs to be backed-up does take much longer than TM usually does, and uses a considerable amount of CPU - - your Mac may slow down noticeably, and if a TM backup is also running, well, it may slow down, too. But won't cause corruption.

If both are running to the same disk drive (not a good idea), they'll both run slower, partly beacuse they both need some CPU, but mostly because all the data is squeezed into the same "pipe." But again, no corruption.

My only advice would be to avoid running both at the same time if they're going to be large backups (ie, after an OSX upgrade or other massive changes) -- but just because you may find other things running rather slowly.

Randy Knowles wrote:

. . .

Time Machine backs up to the partition named "(c) miniStack 500" (not bootable). CCC backs up to the partition named "Boot B-U Macintosh HD" (bootable).

That should cause no problems at all (other than possible minor slowdowns if both run at once).

The only downside to that is, you've got all your backup "eggs" in one basket -- the Seagate. When it fails (and they all do, sooner or later), you may lose both backups. It's rare, but there are threads in this forum where an internal HD failed, and a restore was just getting started when BAM! the backup drive failed, too.

For best results, use a different drive (preferably a portable) to make periodic backups, and take it to a secure off-site location, such as your safe deposit box, workplace, relative's house, etc. That way, you're also protected against fire, flood, theft, etc., as well as failure of the Seagate.

Boy, that worked just like magic...... you're in excellent hands now!

In all honesty I doubt the TM backup or the CCC backup are the problem. It is my opinion that it is the Seagate GOwhatever drive and or that it is a Firewire drive that is the problem. there are posts all over the net of problems with these drives either used with USB oand especially with Firewire and especially on a Mac.