fusion data structures are invalid

I also has ended up with repartitioning my fusion drive and formatting it. After restoring from back up I was able to update to Catalina.

Interesting fact is that running Disk Utility app in recovery mode doesn't help.

It says that repair process failed and this is it. "Very informative".

Looks like the only way is to erase and format partition and restore from backup which is a hassle giving the fact that everything works fine. Just can't update to Catalina and Disk Utility reports error mentioned above. Not sure if this is real error or some Apple bug.

I wonder if Catalina update itself has screwed up fusion drive metadata. It wasn't any signs of issue with it before.

WTF? Thank Jobs (not Cook!) there is TimeMachine. I restore from there. Another 48h23min to go, though...

I have the same problem with my iMac (27-inch, Late 2013) with 3TB fusion drive. Looks like Apple screwed up again.

But my error is

error: (oid 0xd28a5c) wbcl: invalid o_cksum (0xa0ddc495d55bbae0)

Fusion data structures are invalid.

The volume /dev/rdisk2s1 could not be verified completely.

Since everything works fine and there is no any signs of issue it's likely some bug in checking utility which false reports the issue. Or during Catalina update process fusion drive meta data have been corrupted due to SW bug in update utility and now it's the actual issue. Either way if our case is not massive then most likely Apple will do nothing with it unfortunately. I plan to wait for a while if some solution will pop up. If not then to erase and reformat partition and restore data from backup. The only other option is not to update to Catalina.