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

Question

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

Answer 1

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.