Fusion data structures are invalid
So today, all of a sudden, strange symptoms appeared on my new (purchased last December) 21.5-in 2019 iMac , such as
- Some apps just won't load (I click them in the Dock, but nothing happens -- and Activity Monitor does not show any trace of them)
- Some apps seem to load at first, but then (before showing their GUI) they appear as "not responding" in the Activity Monitor -- and they kick the CPU usage to ~50%, slowly eating up RAM and keeping accessing hard drive (one of these apps, in roughly 1 hour, progressively ate some 8 GB of RAM and accessed more than 150 GB of files on hard drives according to Activity Monitor, before pushing the OS into a kernel panic)
- Mail.app says that there is something corrupted in mail boxes data, and that it needs to repair them, but then gets stuck in a loop of "click Exit to repair" > "data is corrupted" > "click Exit to repair" > and so on and so forth.
- Just browsing through folders in Finder sometimes triggers the rainbow spinning wheel, and I have to wait for a few minutes before gaining back control.
- Other apps just work (like Safari, for instance).
So I decided to run a disk check in Disk Utility, and this is what I'm getting:
[...]
error [...] fusion_mid_tree: bin: invalid o_cksum [...]
Fusion data structures are invalid.
The volume /dev/rdisk2s1 could not be verified completely.
[...]
I rebooted into Recovery Mode, performed the same check, but was thrown the same error message. No option is presented to fix the problem.
I also tried the Diagnostics tool at boot-up, but it failed at finding / reporting the issue.
Luckily enough, it seems that I am still able to boot normally (tried Safe Mode as well, but symptoms are still there) and was able (apparently! Fingers crossed) to perform complete refresh of Time Machine back-up on an external drive that I use for this purpose.
Unfortunately, the iMac is not usable.
So I might be in the position to reformat the Macintosh HD, hoping that this will fix the problem, and then restore all of my apps and data via Time Machine backups. Only, I'm afraid that the issue I'm facing is related to some sort of hardware (disk) failure, and that I will be wasting my time.
Any clue?
Thanks a lot
Sergio
iMac 21.5", macOS 10.15