Carbon Copy Cloner corrupts Time Machine?

Randy Knowles wrote:

. . .

My last CCC backup before the Software Update hang was way back on September 16h.

Yes, that's awhile. 😟

I'm thinking that, if I resolve this question about corruption of TM by CCC, I should set up CCC to run automatically as well.

Yup, good plan!

If both TM and CCC run automatically, how does one prevent them from running at the same time?

I really wouldn't worry about it. There is no "cross-corruption" issue, so the only possible problem is reduced performance.

I have my Mac set up to wake up early every morning, while I'm still snoozing. (CCC can now do that automatically). Usually, a TM backup will run almost immediately after wake up, so my CCC clone is set to run a few minutes later. But if they both run at once, it won't bother me, 'cause I'm still snoozing!

You can't easily set TM to run at predetermined times; it runs hourly when your Mac is awake, or when it wakes from sleep (unless a backup ran in the prior hour). When you power down or restart, it runs an hour later (and resets the start time).

What I do personally is back up via Time Machine to a hard drive hooked up to an old Mac Mini and shared over the network. I also have two other hard drives that I back up to using CCC. Only one of those drives is at home at any point in time, while the other lives in the safe deposit box at the bank. Every now and then, I will go to the bank and swap drives, so that the one at the bank is at least moderately up-to-date. In addition, I have a few old hard drives that I have copied important data onto for archival purposes. Those drives are now safely tucked away somewhere, guarding against potential corruption creeping into all the main backups. I add new archives periodically, usually when I retire an old drive in favor of a larger one.

The only flaw in my backup scheme, as I see it, is that my off-site data is not kept as up-to-date as would be ideal. For my particular situation, most of my most valuable files are older files, and I'm not creating new and irreplaceable files with great frequency now. So I'm content with how it works now, but for someone else, adding a cloud-based backup service like CrashPlan or Carbonite might make a lot of sense. But only as a secondary backup... you should still have at least one primary backup of your entire system on a local hard drive, preferably more.

Randy Knowles wrote:

Pondini - Wow, you know I have just been thinking about that, too! I have just started investigating getting another external HD or perhaps a remote backup service via the web? Or maybe both in order to address your suggestion about a backup being stored off site.

🙂

I know nothing about backup off site via the web. How reliable is it? Would I get my normal speed (3.28 Mbps upload) using such a service? How expensive do such things run? Any other comments would be appreciated.

It seems to be reasonably reliable, but you never know when one of the companies is going to go out of business. And be sure the backups are encrypted (how to be absolutely certain, I don't know). Check the reviews of Mozy, Carbonite, and the like -- as with most such things, you'll see raves as well as disasters.

You would probably get roughly your normal upload speed (depending on connection type, possibly time of day, etc.), which will be considerably less than the theoretical speed.

Backing-up your entire system that way, however, doesn't make a lot of sense to me. As far as I know, you can't do a full system restore from them the way you can from a clone or Time Machine. (And if you could, it would take a long time, even over a fast connection.) So what sense does it make to back up OSX and Apple Apps? If you have a catastrophe, you'll either get a new Mac with OSX on it; or a new internal HD and either you or the repair service will install OSX.

However, using something like Dropbox (which I use), SugarSync, or the like to back up relatively small things that change frequently is probably a good idea.

Personally, I keep a CCC clone onsite, TM backups onsite (multiples, partly because I used to do a lot of testing of TM), plus a portable external in my safe deposit box (it's large enough for both CCC and TM partitions, so I put them both there, but a clone is plenty). And, I use DropBox for some other things, like the source for my website, some documents, preferences, etc., that tend to change frequently.

You might want to peruse Time Machine - Frequently Asked Question #27 for some other possibilities.

Randy Knowles wrote:

. . .

So I guess I need at least 3 or 4 external HD's. 1) for TM, 2) for CCC, 3) For off site TM and CCC, and 4) as a duplicate off site drive.

Start with 2. Local for CCC and TM, plus an off-site for CCC (and/or TM), as long as it's updated regularly.

When you can, add another local so you can split CCC and TM.

To be super safe, yes, swap a 4th with the off-site drive so there's always one off-site (I only have 1).

And consider DropBox (2 GB is free) or the like for critical frequently-changing stuff.

As noted on that webpage, backups are not a "one-size-fits-all" sort of thing -- what's great for one situation may not be the best for another.

Wow, and I was just thinking that getting the Thunderbolt adapter for my Seagate was going to be expen$ive!

I wouldn't do that for backups. With both TM and CCC, once the initial backup is done, subsequent backups are "incremental" -- only additions and changes are copied. So the speed of the drive doesn't make much difference. FireWire does seem more reliable than USB, but that's not a certainty -- depends more on the individual drive.

Initial attempts to restore using Time Machine repeatedly failed...

There are many reports on this site of strange problems when using "GoFlex" devices with Time Machine. I suggest you use something else.

A slight diversion, I use CCC to make a daily incremental clone of my drive, it's a fast procedure as only the days (or 2 if I missed one) changes are stored. I like the clone because (in a catastrophe) I can just reboot from it, but that leaves data potentially out of date (by a day or 2) so I use an online system (for data only) that backs up in real time, this satisfies my need to have data offline, and this could be done using TM instead, but then I would have to remember to take the drive home and bring it back .... and that is where the system's weak point is located. 🙂

Wow, and I was just thinking that getting the Thunderbolt adapter for my Seagate was going to be expen$ive!

Yeah, what we've just thrown at you can get a bit pricey, to buy all those drives. Especially if you've got a lot of data that needs to be backed up.

Keep in mind that what we're recommending is a comprehensive strategy designed for someone who cannot lose any of their data. Although what we're recommending is important to ensure the least possible chance of data loss, you have to decide how far you want to go with that, which will include an evaluation of the value of your data. Some people can lose every scrap of data on their hard drive with complete indifference, and for such a person, a backup strategy like mine makes very little sense.

So, you have to decide how valuable your data is to you and what lengths you are willing to go to to preserve it. You may find that your data is not quite so important to put you at our end of the scale, and if that's the case, that's okay.

babowa wrote:

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

Thanks for jumping in. Although lengthy, it's a very useful thread and hopefully will get the attention of AppleCare techs and eliminate the FUD some are passing out, vis-á-vis CCC. 😉