Time machine backups no longer work on OS Catalina

To enable Finder to show extensions you need to open Finder's Preferences then click Advanced and then enable the "Show all filename extensions" checkbox.

Are you doing TM backups to a Time Capsule disk?

As far as changing the "backupbundle" back to "sparsebundle" the MacWorld article says they didn't test this, they say they've been told by some reader -- I would not recommend doing this until you find someone who has successfully tested this who you know or trust. Don't be Macworlds guinea-pig ;-)

I did more research and found people who did try this renaming, but they had the restore hang halfway thru, so this might not be such a good idea. See https://discussions.apple.com/thread/250624630 for this discussion. But this article did talk about using the Migration Assistant to later retrieve the stuff from the backups without the funky name change, so that seems like a better solution in my opinion.

So, I think what happened in your case is that you used TimeMachine under Catalina to do a backup of your Catalina system and you had to specify which disk to use as the destination of TM backups and you chose your TimeCapsule disk. Is that correct? And it created some backups and now you're trying to retrieve something? If this is not the case then please explain a little more of the situation you're now in, and what you're trying to accomplish.

Good luck...

I have the same problem and have lost loads of data - I won't bore you - and spent hours and hours online and on the phone to Apple. I found this this evening https://www.macworld.com/article/3445481/can-t-find-your-time-machine-backup-after-upgrading-to-catalina-look-for-a-backupbundle.html

"Catalina performs a Time Machine backup, it updates the extension on the special package used for these archives. It changes the file’s extension from sparsebundle, a disk image format that can be mounted and browsed like a physical volume, to backupbundle. " Read the whole article as it might not be appropriate for you. I'd do this myself as the backup is unusable as it stands now anyway but I don't know how to find the file extension which is enabled already but doesn't show in Finder window for my external hard drive. I started to do it in Terminal but I can't find either file name so I may be doing it wrong. If anyone can help with this I'd be most grateful.

You appear to have the same problem as others here -- you have two "Data" partitions I will bet. Try these Terminal commands to confirm and copy/paste the commands and the output of all (you need to type enter/return key after each of these):

diskutil list
df -kt
ls -la /Volumes

Good luck...

Thanks for your replies.

I have already enabled the Finder to show extensions but they don't work on my Time Machine external hard drive for some reason which I cannot discover.

I did do more research - not sure exactly who these people are but they seem to be involved in the beta testing of Catalina or their own version of it. https://forums.whirlpool.net.au/archive/98mz6153 If you search the page for 'sparse' and the first mention you get is this

'Catalina TM has now overwritten my existing backup and renamed it. File seems to be there, whole 274gb of it, just can't go back in time to restore.

Installed Catalina on an old Mac lappy – Could see the SMB share on install and do a full restore and access SMB shares.

Installed Catalina on new Mac lappy – Bypassed full TM restore on install. Get to desktop, TM SMB share works a treat. Dunno what happened first time I installed.

Load TM up, select the disk/share to restore from, then I saw the sparsebundle file disappear and a new one pop up with a new name... However, the disk is still showing 274gb of used space.

Can I access the old sparsebundle image?'

There's a lot of stuff there but you have to trawl through it if you want the whole story.

What happened in my case was. After the upgrade I was copying some files to a USB hard drive as I only run the Time Machine when I have made a large change. I left it running and went to bed. In the morning the computer had crashed (apparently this is a thing with Catalina), the usb drive was fried and all the files lost.

I backed up my machine to Time Machine twice - it failed once and the second time the data file appeared but the disk drive wouldn't disconnect. I assumed it was Spotlight but it wouldn't disconnect after having the whole night running. I had to force quit.

I had been using iPhotos and having tried Photos once and found it cost me loads of money in data charges with it synching with my phone I decided I didn't like it but there was one photo left in it and so it didn't offer the automatic migration of my photos from iPhoto. I checked how to do this and did it. For a day they were all there and it was fine but when I started up my computer the next day everything after 2017 had gone. Apple Support just kept me on the phone for hours and skirted around the main issue. After various other issues I decided to revert to Mojave and restore from my TM. The install crashed in the first few minutes. The data was still on the drive and was insufficient to allow another install (though it had been a few moments earlier) but the start up disk was gone. First aid did not restore it. I could not access any of it. Apple Support could not help. I erased the disk. It wouldn't let me install from my Time Machine back up. It would only allow another Catalina install. When I tried to migrate the information from my backup during start up it couldn't do it. Apple said all I could do was start afresh and manually copy and paste files from the back up. After some more hours on the phone they decided that the Time Machine back up of my Bookmark.plist was not included in the Time Machine backup and all of that data is lost. They blamed my hard drive. I blame the program which fried my usb and probably had a similar effect on the external hard drive. It seemed to me that this change in back up name may be responsible for the loss of that data and as I'm prepared to risk a backup which is already less than useless and which Apple say I will have to blow away anyway to ensure the disk is working properly, I'm going to give it a go with the help of the script which dot.com kindly provided.

So a warning. Do not leave disk drives attached when you don't have to. Don't try and revert to Mojave - you can only do it after erasing and even then there is a possibility it won't work - it didn't with mine. Be very sure before you start that you have all the data secure and not buried in TM where you can't tell if it is there or not. I'm seriously considering doing manual Backups. OS you can download - why do you need a back up?

The change in names from sparsebundle to backupbundle appears to be a Catalina specific thing. Changing the name would only make sense if you needed something besides Catalina to be able to read/use the TimeCapsule backup, and may not really be necessary.

I tried creating a backup on a TimeCapsule in Catalina and saw that it indeed had changed the backup image file from ending in ".sparsebundle" to now end in ".backupbundle". I tried to mount that on a High Sierra system and it worked when I simply used the "DiskImageMounter.app" to open and mount it (DiskImageMounter.app is located in /System/Library/CoreServices folder -- by the way, DiskImageMounter.app is the app that will open/mount "sparseimage" files also). I did not try and use TimeMachine to see if I could restore something from it, but at least High Sierra was able to mount the "backupbundle" and was able to look at it's contents and it certainly looked like a normal TM backup.

If I find out more info, will post more later...

Good luck...

Thanks for trying and for the information. I will have a look for the app. I don't think you would have problems from High Sierra.

As I understood it from the bits I read. Should you restore your TM back up from Catalina it changes the name from sparsebundle to backupdundle. Should you then try and restore it again it searches for 'sparsebundle' which no longer exists and so the restore fails.

As Catalina has also corrupted the backups I did when using Catalina it is possible that it simply corrupted all the TM backups I accessed whilst using it. It is possible that my external hard drive is faulty - though a disk first aid finds no faults and I had no problems with it until I installed Catalina (which also fried a usb flash drive).

I also found today that the migration to Music has meant that I can't access all of my songs. It says my computer has not been authorised and asks for my Apple ID but nothing happens even after I have entered it. These songs are stored on my computer not the icloud and they were purchased using the same Apple ID as some that I can access.

I'm just about to go and try to find a solution to this but just in case anyone else should feel tempted to upgrade - I'd wait a bit until they've got the bugs out of it.