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Level 8

38,863 points

UPDATED: Serious Time Machine bug on Mountain Lion

This is continued and summarized from a previous thread, Serious Time Machine bug on Mountain Lion, which has grown rather large and unwieldy (and which I marked Solved in error). There are a few other threads that touch on it as well.

Some of us have seen a few cases of a pretty nasty problem with Time Machine backups on Mountain Lion. It doesn't seem to affect a lot of users, but those who have it, don't know it. It seems to have started at different times for different users, some as long ago as December, 2012.

The backups cannot not be used to do a full system restore from recent backups -- they don't appear on the selection screen that shows only "complete" backups. Plus, they're not recognized as backups by Setup Assistant or Migration Assistant. They don't appear on the Select the Source or Select Your System windows at all. But your user data is fine via the Time Machine browser (the "Star Wars" display).

What's happening is, the top-level Applications, Library, System and (hidden) private folders are being excluded by some process (not the user, and the exclusions do not appear on the Time Machine Preferences window). But all backups complete normally, and Verify Backups from the Time Machine menubar on network backups, and Verify Disk or Repair Disk via Disk Utility, don't show a problem (because what's there is intact; those processes can't tell that what's missing isn't supposed to be missing.)

In addition, we've seen a few threads where the problem is intermittent -- backups are unexpectedly large, sometimes often, sometimes less so, intermittently. In those cases, the folders are backed up, then skipped, then backed-up again, then skipped, etc. Since they appear to be "new" when backed-up again, they're backed-up in full, making backups of 15 GB or more.

See #D10 in Time Machine - Troubleshooting for an easy way to tell if you're affected, and a fix.

However, as we have no clue as to the cause yet, we need to be sure Apple knows about this, in detail, while it's happening, so I'm asking for some folks who are having these problems, and are fairly comfortable with the Finder at least, and following directions to do other things you may not be so familiar with, to help us collect information and contact Apple before running the fix in the link above (as that will destroy some of the evidence).

We're especially interested in folks who are covered by AppleCare, as you can call them for free and get some fairly quick attention. We can supply some "ammunition" for when you call them (since I haven't had this problem, and don't know how to reproduce it, I can't report it myself).

If you're having this problem and just want to run the fix, by all means do so (and check it periodically), but please don't post back with just a "me, too" post, unless you have something significant to add -- this thread may get long and those won't really help.

But if you're having a different problem, please do not respond to this thread. Start a new one, instead. If you're not sure how to do that, please go to the main Apple Support Communities page; some Tutorials are listed at the right. They'll show you how to get started.

Posted on Jun 24, 2013 6:48 AM

171 replies

Ensatina

Level 1

21 points

Aug 1, 2013 8:25 PM in response to Pondini

Hi Pondini!

You helped me a lot a few months ago - and now that I finally got a new MacBook Pro, I want to back it up - but had some questions and I thought of you.

But here I find you - grappling with this problem! So now, my question has changed a bit... should I even use Time Machine given this problem? If not, any suggestions about what to use?

And if you think it's okay... I'm trying to decide whether to "inherit backup history" or start with a fresh back up.... and what advantages there might be to each (FWIW: Apple migrated all my files from my old computer, which I still have - though it's not in the best shape).

Of course, I understand that whatever I do, I'll need to back up on another external as well....

Finally, if I do use TM, what should I do to make sure it's working? Since I'm on AppleCare I could help report this bug to Apple if it hits my computer.

I hope it is okay to post this here... seems I won't be the only one wondering about this! - Thanks.

Message was edited by: Ensatina

Pondini Author

Level 8

38,863 points

Aug 2, 2013 5:22 AM in response to Ensatina

Ensatina wrote:

. . .

should I even use Time Machine given this problem? If not, any suggestions about what to use?

Yes, if you're otherwise comfy with TM, by all means use it (but see below) -- this problem doesn't seem to affect very many users, but of course can be disastrous to those who don't know it until it's too late.

And if you think it's okay... I'm trying to decide whether to "inherit backup history" or start with a fresh back up.... and what advantages there might be to each (FWIW: Apple migrated all my files from my old computer, which I still have - though it's not in the best shape).

That's purely for convenience and to save some space on the backup drive. Normally you'd have little reason to go back to the Applications, Library, or System folders from the prior backups anyway, so as long as the recent/current backups are ok (see below), it shouldn't make any difference.

Of course, I understand that whatever I do, I'll need to back up on another external as well....

That's always prudent. 🙂 I always recommend using another app as well. See Time Machine - Frequently Asked Question #27 for more explanation and some alternatives.

Finally, if I do use TM, what should I do to make sure it's working?

Periodically verify that it's backing-up what it should (per #D10 in Time Machine - Troubleshooting), until we know it's fixed.

Since I'm on AppleCare I could help report this bug to Apple if it hits my computer.

Great! Post back if that happens.

I hope it is okay to post this here... seems I won't be the only one wondering about this! - Thanks.

Absolutely!

Ensatina

Level 1

21 points

Aug 2, 2013 7:59 AM in response to Pondini

Ok - I'm a little unclear about starting a new back up OR inheriting the history...If I'm not too worried much about space on the back-up drive, wouldn't it make sense to start fresh and keep the old TM in case I'm one of the few who has this problem? - in which case, I'll still have the applications etc that seem to be the items that are hit? (I neglected to say that I don't yet have the other drive.... but need to back up now - that's why it's an issue) Only other question: If I start fresh and there is a problem, will this computer recognize the old TM back up from my old computer?

Thanks!

Pondini Author

Level 8

38,863 points

Aug 2, 2013 9:26 AM in response to Ensatina

Ensatina wrote:

. . .

wouldn't it make sense to start fresh and keep the old TM in case I'm one of the few who has this problem?

No. Just check now. It only takes a few moments.

Whether you're affected or not really doesn't matter, unless you don't check -- if you're one of the few, and the existing backups aren't complete, there's no way to make them complete. Just fix it (per the above link) and do a new backup -- it will be complete. End of problem (as long as you keep checking periodically).

If I start fresh and there is a problem, will this computer recognize the old TM back up from my old computer?

If you have the problem, and don't fix it, no Mac will recognize them for use with a full restore or Setup/Migration Assistant. You can still recover your home folder(s) manually, but that's incomplete and difficult.

There's no downside to inheriting; only upsides. If you don't inherit, you'll need the Browse Other Backup Disks option to see and restore from the old backups (per Time Machine - Frequently Asked Question #17).

Ensatina

Level 1

21 points

Aug 2, 2013 9:33 AM in response to Pondini

Sorry - I wasn't clear

- I was on Snow Leopard on the old computer, this is my first time on Lion and I have yet to back up at all.

Pondini Author

Level 8

38,863 points

Aug 2, 2013 9:38 AM in response to Ensatina

As far as we can tell, this problem affects only a few users running Mountain Lion.

So it's not a factor. If you just got a new Mac, it's Mountain Lion (10.8), not Lion (10.7). If you transfer to the new Mac via Setup Assistant (including Computer Settings), when you run the first backup of the new Mac to the old backups, you should get the "Inherit" prompt.

When it's done, and periodically thereafter, just check to be sure you're not one of the few affected.

Ensatina

Level 1

21 points

Aug 2, 2013 9:56 AM in response to Pondini

Aurgh yes! I'm doing it again, I am on Mountain Lion!

Apple already transfered everything I just need to do my first back up... and I am bring promted to inherit or set up a new back up. So you'd just inherit? Even though I *might* become affected and lose the affected items?

Pondini Author

Level 8

38,863 points

Aug 2, 2013 10:02 AM in response to Ensatina

Ensatina wrote:

. . .

Even though I *might* become affected and lose the affected items?

You're misunderstanding the problem completely. 😟

There's no mention anywhere that you're going to lose anything.

Please review #D10 in Time Machine - Troubleshooting. All that happens, to a very few users, is: the top-level Applications, Library, and System folders don't get backed-up on some or all backups. It's easy to see if you're affected, and if you're one of the minority, easy to fix for future backups.

As always, it's always prudent to make secondary backups. If you have those, with a different app, you're covered.

Ensatina

Level 1

21 points

Aug 2, 2013 11:14 AM in response to Pondini

I'm really sorry...I guess I am still unclear on the concept....

I don't understand why you say:

There's no mention anywhere that you're going to lose anything.

while in #D10 you state:

"Not having those folders means not only have you lost the backups of your extra applications, but the affected backups cannot be used to restore your system via the Recovery HD, or with either Setup Assistant or Migration Assistant (the Assistants don't even recognize the drive or sparsebundle)."

I do understand the act of inheriting my old backups isn't a problem on it's own... if that's what you mean.

So it still seems to me, if I should happen to be one of the very few and I'm affected *later on* - after my oldest back ups have sloughed off the external drive, that I will have completely lost the back ups of my extra applications... but if I keep my old TM - I could go there and restore them... (until I can afford to get that second external drive...then I'll be covered.)

Pondini Author

Level 8

38,863 points

Aug 2, 2013 11:20 AM in response to Ensatina

Ensatina wrote:

. . .

if I should happen to be one of the very few and I'm affected *later on* - after my oldest back ups have sloughed off the external drive, that I will have completely lost the back ups of my extra applications...

Only if you don't check periodically. If you do, and find you're affected, run the fix and another backup, and the missing items will be backed-up.

You won't be able to restore the missing items from the affected backups, but you will from the unaffected ones.

And if you have secondary backups, made with another app, you'll have copies there, too.

Sorry, but I don't know any other way to say it.

Message was edited by: Pondini

Ensatina

Level 1

21 points

Aug 2, 2013 12:17 PM in response to Pondini

Okay, that's the part I missed - thanks for all your help.

Pondini Author

Level 8

38,863 points

Aug 2, 2013 12:22 PM in response to Ensatina

😎

chiquon

Level 1

0 points

Aug 5, 2013 2:30 PM in response to Pondini

I've just discovered that we've had this problem on my wife's mac. Painfully I only found out when Migration Assistant would not recognise any of the back ups.

Thankfully one of the biggest jobs for us (copying over Mail folders) turned out to be simple as the whole lot could be done at once. Itunes worked the same way.

I've been able to restore bookmarks through the local Library files that we not omitted by TimeMachine.

Luckily none of our other Macs are affected....

Time to download another backup utility!

Aug 6, 2013 4:51 PM in response to Pondini

Beautiful information. You must be one smart feller.

I have attached the requested files I think. Also some screen shots showing the files not backed up and I am hopeful of one that shows the new back up with system folders etc.

It was just circumstance that I actually looked for a preference file for a network I accidently fouled up and found that since January TimeMAchine stopped backing up the system folders. Now it does back them up on my MBA. I will do my best to follow the Report bugs to Apple directions.

I don't know how many updates have been released since January but it is obviously only an iMac Problem.

Please let me know if you need any more information. I will try to post this information to your chain but am not sure how. Trial and error like everything!

Also attached are the screen shots showing the files did back up once but then the latest showing no backup of those same files as well as the .zip file created by your terminsal command and the old Preference pane.

I hope this helps. It sure seemed like it would help me. I did the reset of TimeMachine and it appeared to behave just like you said so I think it will do the backup which it is doing now. Also attached screen shot of the back up drive details

For everyone. It is an iMac backing up to a miniStack Classic.

Thank you so much for all this free education! Will advise if the new reset TimeMachine does the whole backup. Cannot put screen shots here I guess.

Message was edited by: Vince Egan

Pondini Author

Level 8

38,863 points

Aug 6, 2013 5:38 PM in response to Vince Egan

Vince Egan wrote:

. . .

I have attached the requested files I think. Also some screen shots showing the files not backed up and I am hopeful of one that shows the new back up with system folders etc.

Sorry, but you can't attach things here. You can post small images like screenshots (via the Camera icon in the toolbar of the edit window); or copy small files and post them directly; or post files elsewhere and put a link here. But posting here won't help much -- they need to go to Apple.

I will do my best to follow the Report bugs to Apple directions.

Great!. You'll need the output of the tmdiagnose command, as long as it was run before the fix.

Don't hesitate to post back if you need more info, and let us know how you contacted Apple -- if via AppleCare/Support, or filing a Bug Report. If you don't mind, please send me the AppleCare "Case Number" or Bug Report number to the address on my Contact page, and be sure I know to associate it with you.

I don't know how many updates have been released since January but it is obviously only an iMac Problem.

No, it's not. It has affected all sorts of Macs, starting at least as far back as November. It seems to be related to use of some 3rd-party app(s), but we don't know that for sure, much less which one(s).

UPDATED: Serious Time Machine bug on Mountain Lion