time machine is deleting all my old backups after moving to different iMac

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Level 1

127 points

time machine is deleting all my old backups after moving to different iMac

Hi - I had to move my data to a different machine and so I prepared a different iMac (early 2008). This is what I did:

I booted into Snow Leopard from my DVD
erased the HD
installed SL 10.6
booted into SL
ran software update to upgrade to 10.6.8 (to get the App Store)
installed Mountain Lion 10.8.2
used Migration Asistant to restore all my data, apps, and settings from my time machine backup

This all worked fine and at some point time machine asked me whether to inherit the time machine history. I confirmed this and all seemed fine until I noticed that time machine was backing for a long time and a lot of space was being freed on the time machine volume. I found that it was deleting all my old backups. Before I had data going back to 2010 but now I only have backups left from JAN 2012 onwards.

After some searching I found the excellent Pondini time machine site and performed the actions under B6 ("Reconecting" to your backups):

exxi:~ michael$ sudo tmutil inheritbackup /Volumes/tm2/Backups.backupdb/exxi 
Password:
exxi:~ michael$ sudo tmutil associatedisk -a / /Volumes/tm2/Backups.backupdb/exxi/2013-02-03-150320/exxi_hd

I restarted the backup after applying the command above but it still is deleting old backups. I tried the same comand by associating it with an older backup but still it keeps deleting my backups.

What can I do to stop it from erasing all my backups?

Cheers

Michael

OS X Mountain Lion (10.8.1)

Posted on Feb 6, 2013 3:50 AM

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Answer 1

michaelw Author

Level 1

127 points

Feb 6, 2013 9:13 AM in response to michaelw

Just found this info in the Backup dashboard widget:

Starting manual backup

Backing up to: /Volumes/tm2/Backups.backupdb

Inheritance scan required for /, associated with previous UUID: [deleted]

Event store UUIDs don't match for volume: exxi_hd

Deep event scan at path:/ reason:must scan subdirs|new event db|

First backup after disk inheritance for / - complete scan required

Finished scan

Found 839161 files (154.88 GB) needing backup

188.83 GB required (including padding), 145.37 GB available

Deleted backup /Volumes/tm2/Backups.backupdb/exxi/2012-03-04-160328 containing 2.25 GB; 147.63 GB now available, 188.83 GB required

Deleted backup /Volumes/tm2/Backups.backupdb/exxi/2013-02-05-181442.inProgress/57E7F008-929C-4 DF8-B062-F034FEE7A606 containing 4 KB; 147.63 GB now available, 188.83 GB required

Deleted backup /Volumes/tm2/Backups.backupdb/exxi/2013-01-07-112745 containing 130.8 MB; 147.76 GB now available, 188.83 GB required

Removed 3 expired backups so far, more space is needed - deleting oldest backups to make room

Deleted backup /Volumes/tm2/Backups.backupdb/exxi/2012-03-11-191620 containing 2.08 GB; 149.86 GB now available, 188.83 GB required

Removed 4 expired backups so far, more space is needed - deleting oldest backups to make room

Backup deletion was canceled by user

Deleted 4 backups containing 4.46 GB total; 149.86 GB now available, 188.83 GB required

Backup date range was shortened: oldest backup is now Mar 31, 2012

Backup canceled.

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Answer 2

michaelw Author

Level 1

127 points

Feb 11, 2013 1:11 AM in response to michaelw

As you can see from the log above, time machine had attempted to make a full backup. In the end, I decided to let it run and I'm now left with backups dating back to JUN 2012.

However, this morning I discovered another issue and I think this might explain why it decided to make a full backup.

I scrolled back through my recent backups in time machine and as I went backups from before the switch to the new iMac I found they were all empty. Looking at the time macine volume directly I can still see the files however, I have no permission to read them. All files are owned by "temp" which is a temporary user I created for restoring the backups. I did this because when I first setup the new iMac I used my real account details and then found that I couldn't restore the backups as it was complaining that the user existed.

So I think the real problem is that I setup the temp user as the first and only account when I reinstalled OS X and this meant temp got the UID 501; therefore, all old backups which were created under my real account which also had UID 501 were linked to the temp user. When I created my real account account I was assigned ID 502. Hence the need to create a new full backup.

Not sure what to do now...

Cheers

Michael

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Answer 3

michaelw Author

Level 1

127 points

Feb 11, 2013 1:25 AM in response to michaelw

Looks like I should have read this before I started:

http://pondini.org/OSX/MigrationProblems.html

Cheers

Michael

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