bediron wrote:
Second, I followed the link and tried to disable the SSD portition of the dead Fusion drive from mounting. I attached a picture of that portion. Sure enough, after I used the automount command from the link and disable the UUID of that "Untitled" volume it came up unmounted next time the system rebooted. However, it still crashed after 20 minutes or so with the same kernel panic.
The "Untitled" volume is located on the internal SSD.
I don't see the whole hard drive. What I see is in the picture and I assume the spinning portion is no longer accessible. Just the SSD part. So I don't know whether I can create a tiny partition as you suggested.
If you can get the device identifier for the physical Hard Drive, then we can try to create a very small partition on it...just enough so you can try those instructions again to prevent it from automatically mounting. For example the device identifier for the "Untitled" volume shown in your screenshot is "disk1s2".
I'm guessing your physical Hard Drive will have a device identifier of "disk4", but make sure to replace "disk4" with the actual device identifier of your drive, or bad things can happen to the wrong drive or volume.
Here is the command you will need to partition & format the internal Hard Drive with device identifier "disk4" with just a 50 MB MacOS Extended (Journaled) leaving the rest of the Hard Drive as unpartitioned.
diskutil partitionDisk disk4 2 GPT jhfs+ BadHD 50M free FREE R
If this succeeds, then you should theoretically be able to prevent it from mounting automatically during boot.
This command will not prompt you to confirm anything. And it may erase the drive with the device identifier you provide even if the drive is mounted, so make sure you are using the correct device identifier. FYI, it should not erase any volumes on your boot drive since they are in active use, but still be careful. Disconnect all other external drives just to be safe. There is no safety net when using the command line.
I tested this command (using a different device identifier of course) and it works on a writable mounted DMG image file. However, it will erase the drive even if there are mounted volumes....sometimes even while an app has an open file on the drive (it depends on the app & what the app is doing with the drive). TextEdit didn't lock the drive, but LibreOffice did prevent the drive from being erased in my tests.
I was thinking that I would need to take it to a store and have the physical dead drive removed. Before doing that I rebooted in Recovery and did First Aid on the Samsung external T9 volumes.
The Macintosh HD passed. But the Macintosh HD Data failed. The exit code is 8. The last line says could not verify or repair: -69845.
Sometimes First Aid will fail on the first scan for unknown reasons. Immediately run First Aid again...sometimes it will be able to finish the scan. You may need to click "Show Details" and scroll back through the report which may provide a clue. Just make sure you are running First Aid on the APFS Container which in your screenshot of Disk Utility is "Container disk3". Sometimes the container's file system needs to be scanned & repaired before you can scan or repair the APFS volumes within that Container which include "Macintosh HD" and "Macintosh HD - Data", as well as some other hidden ones (Apple likes to hide things from users....sometimes for good reason as it can simplify things, other times not so simple).
It is also possible you may need to be booted into Recovery Mode or from a macOS USB installer. Some file system repairs can only be performed when booted to other media.
