Big Sur, Big Problems with Time Capsule

Open Time Machine Preferences on the Mac System Preferences > Time Machine

Uncheck the box next to Back Up Automatically

Leave things that way for 30-60 minutes

Then, enter a check mark again next to Back Up Automatically

Restart the Mac

Try again

I would suffer the long phone wait and pay the $95 or whatever the going rate is for Apple Support these days.

At this point, I think you are likely going to have to reinstall the operating system again. Unfortunately, there are no guarantees that this will work.

Not sure if Apple even supports the Time Capsule these days.

Good luck!

I’ve had a long session with Apple during which time we restarted everything to no avail, a PR start, pinged the ram, restarted in safe mode which actually instigated a back up of over 300 Gb which to around 7 hours over the network, but failed to make any further backups. Picking up the courage to continue where we left off, but I’m tending to think that previous comments have it in that there’s no solution until Apple address it.

I just uninstalled it fro the moment. You can 'disable' some of the AV engines online. https://my.sophos.com/en-us/login/

I'll try to re-install Sophos after the first back up and work through the relevant settings. If you happen to work that out before hand, let me know.

Sophos are aware of the issue, and are working on a solution.

They recommend performing back ups in 'safe mode' for the time being.

NB

FYI depending on which chip you're running there are two ways to start in safe mode

Nope. Even if there is a "solution" from Sophos (or Norton, which is also having issues with Big Sur), AV software is not needed on a Mac.

But, don't trust my word, trust the word of the operating system gurus over in the support forums for the Mac operating systems.

I don't use Sophos. I thought I had Avast loaded but looks like I don't even have that any longer, so - no, AV software.

Anyway, since wiping the Time Capsule connected to this MBP now running Big Sur, Time Machine has completed its first encrypted backup about 750Gb, and two subsequent backups. It still seems that whenever Time Machine is Looking for Backup, and for a bit after it is Preparing Backup, the green light for that Time Capsule within Airport Utility turns off, and internet connectivity fails briefly. Otherwise though, now that that TC is formatted vis APFS, the time machine backups ARE working.

I am wondering how to approach my second Time Capsule, which is being shared at the moment by a different MBP and one of my iMac Retinas. The iMac Retina is going to stay on Mojave, but I will upgrade that other MBP to Big Sur also, eventually. When I do, if I wipe that TC, if it ends up formatted entirely as APFS, will the iMac running Mojave even be able to write on that TC's disk any longer? or will only the Big Sur enabled MBP be able to access it?

Otherwise though, now that that TC is formatted vis APFS, the time machine backups ARE working.

The Time Capsule disk.....named "Data", unless you have changed the name of the drive.......is formatted in Mac OS Extended (Journaled). You cannot change this.

If you have "updated" to Big Sur and erased the Time Capsule hard drive, then the format of "Data" remains the same in Mac OS Extended (Journaled). But, the disk image......called a "backupbundle" that contains all the backups of the Mac running Big Sur is formatted in APFS.

So, the format of the Time Capsule disk remains the same, but the backup file is formatted in APFS on the Mac OS Extended (Journaled) drive. Gosh, I wonder what could possibly go wrong with this type of goofy setup.

When you run the backup of your Mohave Mac, the file that stores all the backups might be called a "sparsebundle" file. That disk image will be formatted in Mac OS Extended (Journaled) because Mohave cannot back up to an APFS disk image.

So, the Time Capsule hard drive can store backups of Macs that are running Big Sur and other operating systems as well.

The Mohave Mac will not be able to access the backups made by your Big Sur Mac using Time Machine. But, you could use Migration Assistant on the Big Sur Mac to move data from a backup of the Mojave Mac over to the Big Sur Mac. Complicated? Yes.

I have never had Sophos installed, still had issues with my MBP after upgraded to Big Sur and connected to a 3Tb latest model Time Capsule, until I used Airport Utility to wipe the TC drive and start all over on it. All backups since then have worked automatically without detectible issue.

I actually downloaded and added Avast Security (free version) to this MacBook Pro (MBP) running Big Sur, and it does not seem to affect Time Capsule / Time Machine operation adversely, although I have preferences set to disable Web Shield, and I have unchecked the Email Shield that scans secure connections because this tends to interfere with MSFT Outlook for Mac 2019. Field Shield for Avast is ON.

I am still not clear on whether, for a different 3Tb Time Capsule (TC) of mine, if it is possible to have an iMac Retina on Mojave use that same TC as a different MBP I have that I intend to upgrade to Big Sur - to have two different Macs, one running Mojave, one running Big Sur, both back up AUTOMATICALLY to the same TC.

I also wiped the disc, My wifes air with Big Sur (and Sophos) could backup my MBP not...

Both to the same TC as well.

I had bought a NAS (WD MyCloud), spent hours with no succes so I am very happy it works again.

I am still not clear on whether, for a different 3Tb Time Capsule (TC) of mine, if it is possible to have an iMac Retina on Mojave use that same TC as a different MBP I have that I intend to upgrade to Big Sur - to have two different Macs, one running Mojave, one running Big Sur, both back up AUTOMATICALLY to the same TC.

Possible, since Time Machine creates a separate file for each Mac that is backing up.

I upgraded the second MacBook Pro (MBP) to Big Sur, which this MBP and an iMac Retina running Mojave are both connected to the same 3Tb Time Capsule (TC). That is all I did - nothing more - I did not erase the Data drive on the TC. It has been two days and so far, both computers are backing up without apparent issue to the same TC, so I am reluctant to do any more - to erase the Data drive on TC using Airport Utility and start over I mean.

Not sure why this MBP upon upgrade to Big Sur is having no apparent issues, while the first MBP upon upgrading to Big Sur looks like I had to erase the TC to which it was connected just to get it to start backing up properly.

I still DO notice that when the MBP running Big Sur is in the Preparing Backup stage the green light symbol turns off briefly in Airport Utility but this doesn't seem to affect internet connectivity / router functionality as far as WiFi.

One thing though is that I cannot seem to access the settings of this TC via Airport Utility, whether it asks for the PW or not, it never gets past the spinning circle while it is supposedly "Reading Settings" and then eventually just says that the device was not found and pops an orange triangle by it. Then I quit and reopen Airport Utility and the TC appears again just fine with the green light.

I had the same issue; after upgrading both my and my wife's MacBook Airs to Big Sur, back-ups to Time Capsule weren't working. Fiddled with it off & on for a coupla weeks and discovered the issue was most likely due to Sophos (I'd gotten a hint about that from another thread). Deleted & re-installed Sophos again & again & again - same problem. Used harsh language. Didn't work. Prayed; didn't work. Threatened Air w/going back to my Amiga; didn't work. Let it sit after re-installing Sophos on my Air and it magically began to work. Aha! Downloaded Sophos to wife's Air; didn't work - same problems. Repeated harsh language, threats, etc. then noticed on my Air there were five Sophos files under Security & Privacy - Full Disk Access (where you're instructed to drag/drop files during Sophos install) and on my wife's Air, there were only three Sophos files. When I'd searched Sophos Home Free (using DDG), I found two Sophos sites to download from. Both are certified for-real Sophos download sites, but one of 'em downloads a package that gives you the five files and the other downloads a package that only gives three files. Deleted the Sophos on wife's Air, downloaded from the other site, got the five files where they belong and all is well. Sorry I don't remember which URL I downloaded from.....but DDG it, download & experiment until you get the right number of files from the Sophos install package. I'm thinking that very well may have been the issue I was having w/Big Sur + Time Capsule not backing up + Sophos in the mix. Something in the three-file Sophos package doesn't work & play well w/Time Machine & Big Sur. And they all lived happily ever after. The End.

I had the exact same problem after upgrading to Big Sur. I tried everything, in the end I even erased the disk, still didn't work.

In the end I found out that it was the Sophos Antivirus software which caused the problems. After uninstalling it I was able to create a backup again...