Two Time Machine Mysteries

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Level 1

98 points

Two Time Machine Mysteries

Hi

Yesterday, after a successful Time Machine backup I noticed there were two temporary folders on my Desktop, which I should have deleted BEFORE the backup. Hence I entered Time Machine. First I clicked on the second folder in list view to select it, then on the first one (which deselected the other one) so that only the first folder was selected, right clicked on it and deleted that backup. Unfortunately, after a while, BOTH ( ! ) folders had disappeared! I'm 100% sure that just ONE ( ! ) was selected.

I closed TM. Opened it again (I thought refreshing the view would make the one folder (which I didn't select & delete) visible again, but it really was gone.

A few minutes later, because I had modified a small, but important file, I ran Time Machine backup again and noticed a strange behaviour:

First it said , backing up 100MB of 500MB, then just before reaching the 500MB it said backing up 450MB of 800MB, then before reaching the 800MB it said backing up 750MB of 1.2GB and so on (the target backup size got permanently corrected) until 15GB ( ! ) were copied.

I hope someone can explain these two strange incidents, because otherwise I would question the reliability of my backups.

Many thanks.

iMac (27-inch Mid 2010), OS X Mountain Lion (10.8.2)

Posted on May 1, 2013 12:24 AM

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Answer 1

Best reply

Linc Davis

Level 10

209,535 points

May 1, 2013 7:29 AM in response to coxorange

First, start a second backup on another external drive. One backup is not enough to be safe.

Then repair the backup volume in Disk Utility. If any problems are found, repeat. If there's ever another problem with the drive, replace it.

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Answer 2

coxorange Author

Level 1

98 points

May 1, 2013 10:16 AM in response to Linc Davis

Thanks for your answer!

Linc Davis wrote:

First, start a second backup on another external drive. One backup is not enough to be safe.

I'm using a RAID 1 drive (and copy important files to another Mac), I thought this would be enough.

Linc Davis wrote:

Then repair the backup volume in Disk Utility. If any problems are found, repeat. If there's ever another problem with the drive, replace it.

You think the drive is faulty. But if not, how could the behaviour of Time Machine be explained...?

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Answer 3

Linc Davis

Level 10

209,535 points

May 1, 2013 11:12 AM in response to coxorange

You need at least two backups of all irreplaceable files. How you accomplish that is up to you. Please post the results of the suggested step.

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Answer 4

coxorange Author

Level 1

98 points

May 3, 2013 2:02 AM in response to Linc Davis

Hi Linc

Linc Davis wrote:

Please post the results of the suggested step.

Here are the results:

Verify and Repair volume “MyBook”

Checking file systemChecking Journaled HFS Plus volume.

Checking extents overflow file.

Checking catalog file.

Checking multi-linked files.

Checking catalog hierarchy.

Checking extended attributes file.

Checking multi-linked directories.

Checking volume bitmap.

Checking volume information.

The volume MyBook appears to be OK.

Volume repair complete.Updating boot support partitions for the volume as required.

It seems everything is and was fine.

What could have been the reason for the mysterious behaviour I've reported?

I just would like to know in case something like that should happen again.

BTW: What does the last line mean:

"Updating boot support partitions for the volume as required."

?

Thanks again!

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Answer 5

Linc Davis

Level 10

209,535 points

May 3, 2013 7:33 AM in response to coxorange

1. I don't know.

2. A TM volume is bootable into Recovery mode.

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Answer 6

coxorange Author

Level 1

98 points

May 3, 2013 7:40 AM in response to Linc Davis

Thanks.

Linc Davis wrote:

2. A TM volume is bootable into Recovery mode.

Oh, is this a new feature?

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Answer 7

Linc Davis

Level 10

209,535 points

May 3, 2013 8:02 AM in response to coxorange

Started with 10.7.2 or 3.

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Answer 8

Pondini

Level 8

38,863 points

May 4, 2013 8:34 AM in response to coxorange

coxorange wrote:

. . .

right clicked on it and deleted that backup. Unfortunately, after a while, BOTH ( ! ) folders had disappeared! I'm 100% sure that just ONE ( ! ) was selected.

Sounds like you selected "Delete backup" (ie, the entire backup), rather than "Delete all backups of <folder name>" on the contextual menu:

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Answer 9

coxorange Author

Level 1

98 points

May 4, 2013 10:06 AM in response to Pondini

Thanks, Pondini.

I thougth...

"Delete All Backups of..." means delete ALL previously backed up versions

"Delete Backup" means delete just that one selected backup.

I used "Delete Backup" (there was just one version of that folder backed up to the TM drive).

What do you mean with "(ie, the entire backup)"?

After I deleted that one selected folder (what caused deleting two folders)

OTHER folders continued existing besides the deleted ones (=in the same directory).

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Answer 10

Pondini

Level 8

38,863 points

May 4, 2013 10:30 AM in response to coxorange

Yes, it's not entirely clear from the menu. 😟

The Delete Backup option deletes the entire date-stamped backup -- every file and folder. That backup no longer appears in the Timeline.

The Delete All Backups of <item(s)> option deletes only the backup copies of the item(s) selected, from all date-stamped backups.

There is no option to delete the backup copy of a selected item from only a single dated backup.

If that's not clear, you might want to review the tan box in How Time Machine works its Magic. Referring to the diagram there, the Delete Backup option deletes one of the backup folders, and the backup copies of any items that existed only on that particular backup.

Thus deleting Backup #2 there would delete that backup folder and the backup copy of File C.

The diagram doesn't show multiple versions of the same file; if file B had been changed between the two backups, there would be two separate backup copies of it, and the Delete All Backups of <item> option would delete both of them.

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Answer 11

coxorange Author

Level 1

98 points

May 4, 2013 2:36 PM in response to Pondini

Pondini wrote:

The Delete Backup option deletes the entire date-stamped backup -- every file and folder. That backup no longer appears in the Timeline.

The Delete All Backups of <item(s)> option deletes only the backup copies of the item(s) selected, from all date-stamped backups.

There is no option to delete the backup copy of a selected item from only a single dated backup.

If that's not clear...

Many thanks! *NOW* I see!

In the OS X Mountain Lion online help I had read everything I found about Time Machine, but *THAT* wasn't explained.

I find this extremely dangerous! I just wanted to delete a folder and in fact I deleted my entire backup of that date without knowing it!!! Luckily nothing fatal happend to my Mac until the next backup.

(The following backup should have added all missing data again to the backup drive, am I right?)

Hopefully Apple will add the missing information to the online help. Had you already informed them about this?

Thanks again!

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Answer 12

coxorange Author

Level 1

98 points

May 4, 2013 2:45 PM in response to coxorange

Idea: Before an entire backup is deleted, at least a WARNING MESSAGEshould appear and inform the user about the consequences, for example how many files would be deleted.

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