Upgrade to Mountain Lion - Time Machine silently wiped out my old backups

[RedTomato]

So I finally upgraded my Macbook to Mountain Lion (from Snow Leopard) a couple of weeks ago.

Realised recently I accidentally deleted an important archive folder about a month ago. No problem - go back in Time Machine and restore it.

To my horror, two years of backups in Time Machine are gone

Here's what happened:

On Snow Leopard:
I have Time Machine backups going back 2 years. I restore a file from backup about once every couple of months, so I know it's all there and working fine. The size of the TM backup is around 400 GB with about 50GB free on my Time Capsule and on my Macbook I currently have about 350GB of folders being backup'd. (I exclude downloads, films etc, so mostly it's new email, documents etc being backed up)

Mountain Lion upgrade:
I just downloaded ML from the App Store and followed the default instructions. (I didn't have time to do a clean reinstall). All seems fine. I told Time Machine to warn me if it needed to delete old files to make space. 50GB free seemed enough to handle the OS upgrade, but just in case...

Next morning: Time Machine tells me it's run out of space - it needs to back up 180GB but only has 50GB free. I go into TM and every previous backup is gone! There's only the most recent backup left TM didn't warn me before deleting my old backups I checked TM settings and 'Notify after old backups are deleted' is still checked.

Luckily I have a backup of my TM backup, a duplicate I made about 6 months ago, so I was able to restore some files from that, but some are still gone

Any idea what I can do? Why would upgrading to ML cause 180GB of changes?

Looking into the TC sparsebundle in Finder, it does seem that only the most recent backup is still there

Guess I just have to cut my losses and start a new set of backups.

 

[Macman45]

TM should not have deleted your o;d backup files...I still have stuff going back to SL. Unless you actually removed and started afresh when you upgraded, they should still be there, but may have been renamed....dig around a little on your TC drive.

 

[justperry]

That's bad

So, there is a reason now not to use TimeMachine, luckily I "never" did, I use Carbon Copy Cloner, much better in my opinion and does scheduled backups.

Might try to do a recovery on the disk, you might find deleted stuff.

 

[benwiggy]

I have heard similar stories to yours, however, and I think the main factor is limited space left on the backup. 50 gigs is not a lot. At that point, I would be looking for a bigger drive to transfer my backup onto.

I've upgraded each OS from Leopard through to Mountain Lion, and I've still got files from the 2007 backup. As my backup has grown, I've moved it across three drives, which is pretty easy to do.

I don't know why simply upgrading to ML would need 180Gb. You didn't do anything else, apart from upgrading the OS? Xcode?

 

[RedTomato]

I have heard similar stories to yours, however, and I think the main factor is limited space left on the backup. 50 gigs is not a lot. At that point, I would be looking for a bigger drive to transfer my backup onto.

I have a lot of other stuff on the Time Capsule, which I could have removed if TM had warned me first.

I've upgraded each OS from Leopard through to Mountain Lion, and I've still got files from the 2007 backup. As my backup has grown, I've moved it across three drives, which is pretty easy to do.

I;ve done that too. Leopard ->Snow Leopard -> Mountain Lion including transferring backups off a dead TC

I don't know why simply upgrading to ML would need 180Gb. You didn't do anything else, apart from upgrading the OS? Xcode?

Am baffled too. 180GB is over half of all my data. Did nothing else, no large software installs, no large downloads done. If it had been 350GB, all my data, ok that's understandable, means TM wanted to do a fresh start, but why only half of my data?

That's bad

Might try to do a recovery on the disk, you might find deleted stuff.

Nope its gone. See screenshot of the finder window below. One backup date and one incomplete backup date My other TM backup has a whole list of dates from 6 months ago going back to early 2011.