Big Sur installation freeze after reboot

[jperss10]

The installation starts and everything looks like it should!
Then the computer restarts and the Apple logo and a progress bar shows. It moves I little but then it freezes and nothing happens?!?
I left the computer on over night but it didn't move any more.

Then i have big problems to reach Recovery Mode to reinstall Catalina!
I have run the diagnostics but it found no errors in the system!

I have an iMac Retina 2017!

 

[Cory Cooper]

Hello and welcome.

-Is it the 21.5" or 27" model?
-Do you have the original Apple RAM, or did you upgrade it with third-party DIMMs?
-How much free space is there?
-Do you have a current Time Machine or other backup of your data?

C

 

[jperss10]

Hi, thanks!

It's the 27 and is all original!
There is lot's of space, of 1TB its around 600gb of space left so it shouldn't be any problem!
No haven't any Time Machine or other backup!

Im so confused about this. There haven't been any problems updating before and the computer works as it should!
This came with Big Sur! Catalina installs without any problems!

 

[MartyByrde]

The installation starts and everything looks like it should!
Then the computer restarts and the Apple logo and a progress bar shows. It moves I little but then it freezes and nothing happens?!?
I left the computer on over night but it didn't move any more.

Then i have big problems to reach Recovery Mode to reinstall Catalina!
I have run the diagnostics but it found no errors in the system!

I have an iMac Retina 2017!

Sorry to hear that. On another Mac discussion site I visit, a number of folks there have also experienced issues with 1) downloading Big Sur, and 2) installing it. I refuse to take the plunge now. Will most likely start to test it, on a separate external SSD, after a couple of more versions come out. Besides, a number of my third party applications I use are not yet compatible with it.

As for recovery, what backup method/program do you use? If it's Time Machine, you might want to consider either SuperDuper! or Carbon Copy Cloner. Both of them work fine with Catalina, and both of them make bootable backups/clones. Makes recovery a lot easier.

 

[jperss10]

Today i tried to install in safemode, but same result!
I really dont know where to get help with this....

 

[MartyByrde]

It might be best to wait until a couple of more releases of Big Sur come out. Is there anything you must have in Big Sur? Myself, I see nothing.

 

[Cory Cooper]

Hi,

You're in a tough situation, since you don't have a backup of your data.

Does your iMac have a Fusion Drive or flash storage?

Do you have access to another Mac? If so, you may be able to create a USB flash drive installer for Catalina, and install it on an exteranl drive that you can startup from. You may be able to recover your data that way. Or, you could try macOS Recovery and install try reinstalling Catalina: How to reinstall macOS from macOS Recovery > Command (⌘)-R.

It depends on what state the Mac is currently in, since the installation of Big Sur is failing.

C

 

[MartyByrde]

Yeah, no backup is definitely dangerous! Have you been updating any of your machines to a new OS without having a backup? If you have, you have been lucky so far.

And Cory makes excellent points, and also excellent suggestions. Hopefully you can recover just about everything.

Going forward, it would be extremely wise to make frequent backups.

 

[jperss10]

I have all my data in iCloud so that`s no problem.
Im back in Catalina now and everything workshop fine.

and i`ve tried to install Big Sur in a couple of ways but with the same error when it reboots!

 

[MartyByrde]

Might be better to wait until a couple of more releases of Big Sur appear. On another site I visit, plenty of folks are having issues with it.

Also, what about third party software compatibility? You need to consider that. This site can help:

Application Compatibility Table — RoaringApps

Crowd-sourced application compatibility for macOS, iOS and Windows.

roaringapps.com