avoid Timemachine falling back to internal hdd

These are called Local Snapshots.

Have a read here http://web.me.com/pondini/Time_Machine/30.html about them and how-to remove them.

Stefan

Sorry for the misunderstanding then.

Never heard of such behavior before with TM.

I'm sending an alert to Pondini (the guy who wrote the tutorial and more on TM), maybe he has an idea.

Stefan

sadrian-dev wrote:

. . .

On the issued MB Air, TM switches to "inactive" and automatically sets the internal SSD as backup volume instead of the external HDD. (The SSD also gets the TM icon)

Sounds like the SSD was once selected for use with Time Machine.

See if there's a Backups.backupdb folder at the top level of it. If so, delete it.

Isn't it meant the way, that TM saves snapshots without changing its preferences until I reconnect the external drive?

Local snapshots are entirely separate and independent. They're made when Time Machine is ON, whether the destination for "normal" backups is available or not.

That looks like you have a separate partition named "MacBook Air (internal)".

Start up the Disk Utility app (in your Applications/Utilities folder), and see what it shows in the sidebar.

Each physical drive is shown, with the partition(s) on it indented underneath it. In the sample, I have a 640 GB internal HD with 2 partitions, and a 320 GB external with 6.

Clicking on an item in the sidebar will show various info about the disk or partition.

I think you'll find the MacBook Air (internal) is a partition on your SSD. If so, click it and see how large it is, how much is on it, etc.

That partition may also show on your destop or Finder sidebar. If so, open it. I suspect you'll find another Backups.backupdb folder there.

EDIT: Sorry, I hadn't seen the inset at the bottom of your attachment clearly:

It does look like MacBook Air (internal) is the only partition on your SSD (they're usually named Macintosh HD, even though they aren't really HDs).

Since you've deleted Backups.backupdb and done the full reset (you did quit System Prefs while you did that, right?), I don't know why it's doing that.

Two questions:

When you disconnect the external, are you ejecting it first? That shouldn't matter, but you never know.

Are you running any 3rd-party apps that deal with Time Machine, or using something besides a "normal" external HD (like a NAS device)?

sadrian-dev wrote:

. . .

- I can't remember if I quit system prefs while deleting the TM-preferences - but I should have. I'll try this again tonight.

Good. If System Prefs > Time Machine is open, it has a copy of the (old) file contents. If you delete the file and then close System Prefs, it will put the previous contents in the new file.

With you telling me, TM should not act this way I get more and more curious if this is somehow related to something different. Maybe something went wrong while upgrading from Snow Leopard to Lion?

That's always a possibility. Unusual, but possible.

The reason I asked about 3rd-party utilities or a NAS is, your TM Prefs panel has two buttons at the top that I've never seen before. They look like a couple of buttons that come up on a separate window in some circumstances when Time Machine can't find the selected drive.

You're not running Lion Server are you? I don't think that should matter, but I'm grasping at straws here.

Do you have any thoughts what else I can look for?

Gremlins. 😉

Double-check whether a new Backups.backupdb folder has appeared on your SSD.

Sorry, but this is quite bizarre. I won't recommend it yet, but you may need to contact Apple, or try installing the 10.7.2 "combo" update, or even reinstalling Lion.

sadrian-dev wrote:

. . .

Next step complete reinstall?

Ordinarily, the next step would be to reinstall OSX (OSX only, not your entire system), per Installing the ''combo'' update and/or Reinstalling OSX.

Because of the two extremely odd things you have going on that I've never seen or heard of, though, I'm a bit skeptical this is something missing or broken in your installation of OSX:

The two buttons at the top of your TM Prefs window (on both your Macs); and,

The switch to another destination (much less your internal SSD) when the selected one isn't available .

Did you buy both Macs with Lion already installed?

Or did you upgrade one or both?

If both, did you do them both, separately, via download?

Short of a call to Apple, the reinstall is the only other thing I can think of that you haven't tried.

I've not used Express Lane, but have heard good things about it. In Switzerland, it looks like it's available in Frence or German. Might be worth a try. (Be sure to mention the two buttons, too -- I suppose that might be something unique to the German version, but it seems highly doubtful.)

Either way, good luck, and keep us posted.

Hi,

Another user pointed out that the two buttons at the top of your Preferences window are the same ones on other versions, just moved. That seems to be on the German language panel (and perhaps others). I'd never seen it before, couldn't read the screenshots very well, and since I don't read German, didn't recognize them. So please forget that "issue."

We have seen another user with a variation of the "switching destination" problem, though. In that case, when the external HD used for backups isn't available, it shows the internal HD, but sends a message about "the identity of the backup drive has changed" every hour.

Have you had any luck contacting Apple?

Great news Sebastian 🙂

Manchmal braucht es wohl die Brechstange... 😉

Stefan

sadrian-dev wrote:

. . .

I wiped the SSD and did a full recovery from my TM backup. Voilà! Everything works just as it should! Perfect.

Teriffic! 🙂 (But how very strange!)

It would have been nice to know the cause of the problem - but at some point I lacked the time for further investigation.

Something extremely unusual -- only one similar (but not identical) case I've seen.

The 2 buttons in the TM prefpane translate to "Choose Volume..." and "Options" and still remain when I switch my system to english. Aren't these present in your TM prefpane?

Yes, but in a different place, and yours were a bit hard to read in the screenshots. I've seen a few shots of that panel in some other languages, and all were positioned the same as in the English version:

Why the different placement, I have no idea. Perhaps there isn't enough room for the longer text, but you'd think Apple would just move the buttons for all versions.

FYI, the OP's problem was probably caused by the file tmbootpicker.efi, which is at the root level of any TM volume in Lion. That's what he needed to delete.