Time Machine not working with Big Sur

Kerry_Lee wrote:

I've heard many people are having problems with Big Sur. Good luck!

of course you've seen lots of people with issues here. this is a SUPPORT forum. people are here asking for suggestions on how to fix things. nobody posts here just to say "everything on my mac is nice and rosey" :)

Is your Time Machine drive a SSD or a rotational drive? I use a rotational drive and it is formatted OS X Extended (journaled) and runs fine with Big Sure.

How much free space do you have on your boot drive? If not enough to let it create a local snapshot TM stalls out.

I updated my 2015 MacBook Air to Big Sur.... and now, Time Machine does not work. I go to open it and it opens multiple windows and freezes. I just want to back up my computer to a Lacie external Hard Drive that the Apple Store just sold to me before i bring the computer in for a battery repair the Apple Store says I need.

Is perhaps my MacBook Air not able to handle this operating system. And, if so, why the heck did Apple suggest I upgrade to it?!!!

Luckily, I had enough room left on my 4 TB external HD to make another good-sized partition using Disk Utility: this time I formatted it in APFS though (as opposed to Mac OS Extended [Journaled], in which the external HD with about 2 TB of my old backups was originally formatted. Now the new partition is working like a charm: the "preparing backup" section takes less than 5 min for about 130 GB! (BTW, I'm using Time Machine on macOS Big Sur; on a Retina, 13-inch 2015 MBP.) The only downside, though, is that you're going to have to do a fresh backup, which is going to eat up a little bit more of your new partition, i.e., depending on the size.

Hope this helps!

Poldy

Me on the other hand has issue with TM where the TM drive keeps dismounting while TM is doing the backing up.

The issue is random; sometime TM works but most times it doesn't. The TM drive in on RAID 0 configuration.

it sais: "Format: Mac OS Extended (Journaled)" , its connected through USB. I dont wanna play around with it, cause i dont wanna loose the data on it . The problem should not be the disk since, as i said, did the back up on dec 2 without problems.

I can open it, see the content, enter the Time Machine, i simply can't back up the data. It says "preparing back up" for hours. ( i ejected it, reconnected it, rebooted the pc, etc ..)

If it doesn't get out of the "preparing data" phase you have two options: 1 - run Disk First Aid on it and hope it fixes the problem and 2 - erase the hard drive and start over. That 's what I had to do as it wasn't backing up and always preparing. I haven't had a problem since.

There is a 3rd option: get a new external HD and start using it.

Apple had me copy the backups to a new drive before erasing my AirPort Time Capsule drive for troubleshooting, so I know you can do that. It took almost a day plugged in directly with an Ethernet cable. I'm not sure if you can start backing up again to those copied backups. I'm starting from scratch. The backups to Big Sur aren't supposed to take as long, from what I've read. I plugged into the Time Capsule directly, and it took about 8-10 hours to backup 538 GB on a MacBook Pro (Retina, 15-inch, Mid 2015).

Working with Apple support I tried to copy my backup folder to a new drive, but it failed. The upgrade to Big Sur ended up costing me a pretty penny because I'd only recently bought the 4T backup drive that now is unusable. I backed up to the new drive starting in the late afternoon, and it finished by 6am the next day. Subsequent backups have been speedy.

Despite Apple Tech support's assistance and diagnostics, I had to give up on the backups stored in the older drive. Nothing they suggested worked--and the engineers were in on it, evaluating the diagnostics several times. I'll have to erase the old drive, reformat it for Big Sur, and eat the coast of the new drive. Going forward I'll alternate backups to the two drives so I'll always have one if the other fails.

I have a MacBook Air 2020, and the original backup problem started when I upgraded to Big Sur.

Well, I tried pretty much everything that looked useful from the discussions here, but nothing worked UNTIL:

(I had two backup drives for Time Machine that I alternated, both that had worked until December 10th, which was when I upgraded to Big Sur 11.1. (Originally my backups had been working with Big Sur 11.0 from mid-November, and with 10.x systems before Big Sur).

Both of my original external drives were encrypted with FileVault, under Mac OS Extended (Journaled, Encrypted). One is a 1TB SSD (Sandisk), one is a 8TB HD (Seagate Backup Plus for Mac).

Note that the Time Machine interface for restoring files seemed like it was still working, it's just that I couldn't do any new backups.

Got that same endless message, "Preparing Backup"... didn't matter if I waited 10 hours, it stuck there, didn't do anything, with either drive.

Gave up and copied all of my backups from my 1TB drive to my 8TB drive (which took about 10 hours or so, an overnight job).

Reformatted my SSD using Disk Utility to be the new APFS (Apple File System, Case-sensitive, Encrypted) format.

• (To my understanding, although it's certainly not clearly explained anywhere, encrypted disks replace the need for FileVault...).
  • Turns out I may not have needed to use Disk Utility because when adding the disk back to Time Machine (after deleting it from Time Machine in its prior instance), it asked me if I wanted to format it, which I did.
  • It's OK, formatting the SSD only took 2 or 4 minutes.

Did a backup, it did the whole 150GB of user data that I don't back up elsewhere to the (now APFS) SSD in less than 90 minutes.

Tried the Seagate (8TB) MacOSExtended drive again, in case somehow Time Machine got freed up/unstuck. No luck.

So, if you are in my shoes the solution is simple:

• wait until apple fixes the bug that stopped Big Sur from working with the traditional MacOSExtended drives, go naked on your backups
• reformat your drive to APFS and start backing up like normal. (and lose all your old backups in the process unless you have somewhere you can copy them off to like I had...)

Good luck!

I posted this question when I bought my new iMac in December 2020 with Big Sur already loaded. I understand Time Machine does not work for e-mails with Big Sur as it once did. I kept El Capitan on my old iMac and TM works with MAIL; but with Big Sur and apparently some earlier OS, the easy functionality of MAIL and TM was lost.

E-Mails can still be retrieved from external back-up drive with Big Sur but it is a comparatively messy business, not the easy mail retrieval of El Capitan. I have been through all the hoops with Apple Support and the answer is that we have lost a valuable tool.

FWIW - I have been using Macs for over 3 decades- currently running/using minimacs, one 2018 version for current everyday and one 2014 version for Time Machine backup ( which does not run big sur but latest system 10 ) Changed to big sur in Feb. 2021 Email works but all new email comes in as trash, and until you move it to archive or actual email, reading it is a mess, since if you try to read email A by clicking on it, email B,c, or d comes up instead. As to time machine backups via other mini, or solid state external drive - all seems to be ok.

However- about 10 years ago, I used a free program called SymbolicLinker, which allowed me to assign a partitioned volume other than system volume to contain emails and certain other documents. Required making a change in email application library as it was before system 10. Still works thru all later changes- as long as one keeps the NAME of the partitioned volume the same between and during all upgrades and newer macs.

Might be worth checking out

jeffreythefrog wrote:

+1.

i just did a fresh one in HFS+ (thanks due to the person whose answer i'm making this reply to)

You're welcome.

I had the same issue. Catalina backing up to a Synology NAS using Time Machine, all fine. Big Sur would fail every time. I removed Sophos Home AV and all is now working again.

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