Bootcamp: impossible to partition

Hi LonerT,

thanks a lot for your help.

macOS version:

10.13.6

The Windows ISO is the only one that the microsoft website shows:

Win10_20H2_v2_Italian_x64.iso

I have tried to create a small FAT partition using disk utility to check if creating and deleting a small partition would fix anything. At the end of the partitioning process the computer shut off by itself. On turning it back on, it showed the apple loading screen and at the end of the loading it shut off itself again. Turned the computer on in recovery mode, ran disk utility, upon repairing it showed an error message stating that it was impossible to restore core storage, I ran disk utility again and apparently there were no issues anymore. Upon rebooting, the mac now works again.

But I am still unable to create a BootCamp partition.

I have run diskutil list again, and it shows this

/dev/disk0 (internal, physical):

  #:            TYPE NAME          SIZE    IDENTIFIER

  0:   GUID_partition_scheme            *121.3 GB  disk0

  1:            EFI EFI           209.7 MB  disk0s1

  2:     Apple_CoreStorage Internal Drive     121.0 GB  disk0s2

  3:         Apple_Boot Boot OS X        134.2 MB  disk0s3

/dev/disk1 (internal, physical):

  #:            TYPE NAME          SIZE    IDENTIFIER

  0:   GUID_partition_scheme            *3.0 TB   disk1

  1:            EFI EFI           209.7 MB  disk1s1

  2:     Apple_CoreStorage Internal Drive     2.0 TB   disk1s2

  3:         Apple_Boot Boot OS X        650.0 MB  disk1s3

  4:     Apple_CoreStorage Internal Drive     801.4 GB  disk1s4

  5:         Apple_Boot Boot OS X        134.2 MB  disk1s5

/dev/disk2 (internal, virtual):

  #:            TYPE NAME          SIZE    IDENTIFIER

  0:         Apple_HFS Macintosh HD      +2.9 TB   disk2

                 Logical Volume on disk0s2, disk1s2, ...

                 93A49517-8EF8-430A-B0A4-9090AA7DE6E3

                 Unencrypted Fusion Drive

/dev/disk3 (external, physical):

  #:            TYPE NAME          SIZE    IDENTIFIER

  0:   FDisk_partition_scheme            *15.4 GB  disk3

  1:         DOS_FAT_32 WININSTALL       15.4 GB  disk3s1

Hello,

Encountered a few difficulties on the way, but in the end it managed to reset fusion drive, install OS and restore backup, it took 12 hours!

My new current OS version is 10.15.7

Since it's a more updated OS, should I try to install BootCamp in some different way or keep on with the previous method, with the split up version of Windows?

Thank you :)

So I can't have BootCamp anymore because Apple designed the latest supported OS for my model so that it can't do anymore what was able to successfully do with a previous version?

Looks like if I want to keep on using my iMac as I was before I need to downgrade my OS, or worse I need to buy a newer Mac, not even the newest since M1 chips still do not support BootCamp (although in this case is a Microsoft issue).

I have already tried some alternatives – CrossOver and Parallels – but they both give me very low performance, what used to go at 50-60FPS in previous BootCamp it goes now at 8-10FPS with the virtualization, making it a non viable option.

This sounds like a classic case of planned obsolescence, doesn't it?

Sorry for the rage LonerT, it's not directed at you, but at the choices Apple made which negatively influenced my particular model.

Yes I did make a TM backup and all of my files are backupped. I have followed the twocanoes guide and successfully created a split iso of windows, how can I fix the disk issues?

thank you :)

Thank you for all of your help, Loner T, I will think about it and come up with a solution for my needs.

Have a nice weekend :)