Big Sur Time Machine backup incompatible with Catalina

[Gnomeo86]

Hi all,

I am fed up with how slow Big Sur is on my late 2013 MBP so I want to go back to Catalina. I made a Time Machine backup of my files, wiped up my hard drive and installed Catalina. However, when I tried to restore the backup, the OS couldn't find it on the portable drive. The file is there, but it's hidden and nothing I tried to unhide it worked. So I installed Big Sur again and the backup file was recognised immediately.

Does anyone know how I can use a Big Sur backup in Catalina?

Thanks!

 

[leman]

I dint think you can. Big Sur uses a redesigned Time Nachine that’s faster and more reliable. I don’t think that Catalina supports the required formats.

 

[dotck]

Interesting fact: Apple used the ".sparsebundle" suffix for Time Machine backups until Mojave, changed that to ".backupbundle" in Catalina and reverted to use ".sparsebundle" in Big Sur. You should be able to change the folder suffix for your device and try again (to .backupbundle in your case). I was also able to restore data from a backup created under Catalina in Mojave using that "method". Be aware that not all things may be restored since configurations etc. may change between OS versions.

 

[Gnomeo86]

Interesting fact: Apple used the ".sparsebundle" suffix for Time Machine backups until Mojave, changed that to ".backupbundle" in Catalina and reverted to use ".sparsebundle" in Big Sur. You should be able to change the folder suffix for your device and try again (to .backupbundle in your case). I was also able to restore data from a backup created under Catalina in Mojave using that "method". Be aware that not all things may be restored since configurations etc. may change between OS versions.

I did read about this solution and tried it. However, in Catalina, my Time Machine backup file had a ".previous" suffix Changing it to either ".sparsebundle" or ".backupbundle" didn't help, the file remained hidden and unrecognised.

 

[Gnomeo86]

Apparently, it's simply impossible. I just found this on Apple's website:

1. Important: If you create a backup on a Mac running Big Sur, the backup isn’t compatible with Macs running older versions of macOS.

 

[contacos]

surprised to hear that its slow. I installed it on my late 2012 MacBook Pro which is not even officially supported and it runs great. I will probably keep this laptop another 2 years at this rate.

 

[PinkyMacGodess]

I ran into this with iOS. Even an x.x.1 difference was enough to have the backup not work. It makes Time Machine a rather limited service, and any backup of iOS also limited. Backup compatibility would seem to be an important featrue of any backup system...

 

[Neophyte_FL]

Apparently, it's simply impossible. I just found this on Apple's website:

Would you please provide a link to the Apple reference? If I correctly understand your comment, a computer running Catalina (for example) can't read a Big Sur backup. My burning question is whether a computer with Big Sur can read a backup performed under an older macIOS. This has been my barrier, among other lesser issues, to upgrade to Big Sur as I want to retain access to those older backups.

 

[Gnomeo86]

Would you please provide a link to the Apple reference? If I correctly understand your comment, a computer running Catalina (for example) can't read a Big Sur backup. My burning question is whether a computer with Big Sur can read a backup performed under an older macIOS. This has been my barrier, among other lesser issues, to upgrade to Big Sur as I want to retain access to those older backups.

Here it is: https://support.apple.com/en-gb/guide/mac-help/mh35860/mac

 

[gilby101]

My burning question is whether a computer with Big Sur can read a backup performed under an older macIOS.

Yes. You can use Finder to recover user files/folders from any TM backup created on an older version of macOS. But you would need to be careful recovering settings and apps that way as some would be incompatible with the newer macOS.

The general principle is that operating systems have backward compatibility (understand stuff from the past), but not forward compatibility (understand stuff from the future).

 

[leman]

I ran into this with iOS. Even an x.x.1 difference was enough to have the backup not work. It makes Time Machine a rather limited service, and any backup of iOS also limited. Backup compatibility would seem to be an important featrue of any backup system...

Time Machine has backwards compatibility. Of course, what you say makes a lot of sense - a backup system that radically changes its format every year would be rather annoying to use. But sometimes one needs to do a clean break in order to move the technology forward. This is the first time in ages that Time Machine format has been significantly overhauled, and it does make it much better. Instead of copying and linking individual files like the last TM did, Big Sur is backing up full filesystem snapshots directly. This makes backups much faster and the entire process more robust.

 

[PinkyMacGodess]

Time Machine has backwards compatibility. Of course, what you say makes a lot of sense - a backup system that radically changes its format every year would be rather annoying to use. But sometimes one needs to do a clean break in order to move the technology forward. This is the first time in ages that Time Machine format has been significantly overhauled, and it does make it much better. Instead of copying and linking individual files like the last TM did, Big Sur is backing up full filesystem snapshots directly. This makes backups much faster and the entire process more robust.

I remember the DEC Backup software, and at a conference, a Digital engineer took a tape, cut 20-ish feet out of the middle of it, spliced it back together, and was able to restore a server back to the moment it was backed up. People were floored. I recommended a backup system for our clients that did 'snapshots', and the files didn't have to be complete for data to be recoverable from the files. They did 'epoch' backups infrequently, but you could do a full restore without the entire backup thread. They did backups either to their own servers (cloud), or a local drive array, or tape. I never had a problem with their software and getting files back off it. I've been nervous getting restores off Time Machine, and haven't been disappointed. The problems have always been with iPhones. My 10x Plus had a x.x.1 update, and I could not restore from the backup from my older iPhone because 'it's not the same version'. BUT BUT BUT!!! Apple could not solve the issue, and I waited a few months for the prior iPhone to update to the same level to do a damned backup, and a restore. (I think I had to update both, but then the backup worked, and restore was perfect. Waiting months to use a new iPhone was a great experience)

 

[Giannib]

I dint think you can. Big Sur uses a redesigned Time Nachine that’s faster and more reliable. I don’t think that Catalina supports the required formats.

I've upgraded to big sur, now i need to re install the system from the backup but noticed that all the time machine snapshot are in
macOS 10.14 Mojave format, at least so they are signed from the recovery menu.
Also i noticed the backup are about 5 gigs in size while I'm mojave were about 80 , seen expanding the icon on top right

 

[Tooti]

Same situation here… I just downgraded and cannot restore using Time Machine. So How can I get my data to Catalina ??

 

[PinkyMacGodess]

Same situation here… I just downgraded and cannot restore using Time Machine. So How can I get my data to Catalina ??

Find a catalina machine, put the data on it, and copy it raw off to the other system?

 

[gilby101]

Same situation here… I just downgraded and cannot restore using Time Machine. So How can I get my data to Catalina ??

Can you open the backup in Finder? If so, you can copy your data from there.

 

[Gnomeo86]

Can you open the backup in Finder? If so, you can copy your data from there.

That’s exactly what I did.

 

[Tooti]

That’s exactly what I did.

Thanks ! So you mean dragging each folder manually (library, user, apps…) from the “Big Sur” Macintosh HD to the “Catalina” one ? What happened during the process is that I now have several instances of different Macintosh HD. Some with “data” written. One with my 1,3 Tb of data, the others with 11Gb, or 4Gb… I am kind of lost, do you guys have any tutorial dealing with this issue ?
I basically want to put all my data in one single Macintosh HD under Catalina. I included screenshots from disk utility so you guys can see what’s going on.

 

[kibepo73]

MacOS Big Sur, supports Time Machine on APFS formatted drives. Maybe, that's why you are unable to access the same on Catalina. As, if you want to shift a drive from APFS to HFS+, you have to reformat the drive, and that erases all the Time Machine backups.

 

[PinkyMacGodess]

I ran into this problem with backup software on/for a Windows server, believe it or not. Earlier save sets were incompatible with their current version of the software. Tech support said I needed a 'more recent backup to restore files from'. WHAT?!?! Are you serious? I had the client drop them that day and went with another vendor. You just can't do that to a server, or a customer! Holy cow!! Stupid, stupid, stupid. Just unbelievably stupid. I was able to find the needed file on an earlier save set, but wow. Imagine that being bad or not having the file.

But the iOS issue I had was just stupid too. A 0.0.1 update in the release and I had to sit with a brand new iPhone for over a month that I couldn't use because I couldn't get data from my old iPhone onto it. Note to self: NEVER update anything the days before swapping hardware. Who would expect that such a small update could throw everything into crazy town.

I so feel your pain. On the phone with an 'engineer' at Apple, I was almost shouting that it was such a small update, how many people were having the same issue. The guy chuckled a little and said 'You are not the first person I have talked to about this issue, not at all. And you have actually been the nicest person so far too so thanks for that.' I can only imagine the heated conversations that people at Apple support were having because of that...


I thought APFS could mount an HFS volume?

 

[Tooti]

Is there any solution to get my data on Catalina ? Or do I have to abandon the idea of downgrading ?