How Do I Erase & Mount This Synthesized Drive?

[Alvin777]

Hello, I have a Fusion Drive and run macOS Monterey. When I did a surface test on Windows BootCamp which was a mistake, I lost the SSD part of the Fusion Drive and I fresh installed macOS, I'm only running macOS on the Fusion Drive's 2TB hardisk. This was almost a year ago. I'm still trying to revive my 128GB Apple SSD drive built-in (part of the Fusion Drive).

Whenever I type 'diskutil list' I see a disk1 but it's synthsized. It's not mounted, nor does Disk Utility see it (thus I can't or erase it).

What could be done to revive this systhesized drive?

Thank you.

 

[joevt]

disk1 is the apfs contents of the apfs physical store that is partition 2 of disk 0 (disk0s2). It contains your currently running OS and user files. You do not want to delete it.

It seems to me that your SSD is not accessible at all, otherwise it would be disk1 and the synthesized disk would be disk2. But to be sure, show the full output from the diskutil list command.

In DiskUtility.app, select "View" -> "Show All Devices...". Do you see your SSD in the list of devices? Show a screenshot.

 

[Alvin777]

disk1 is the apfs contents of the apfs physical store that is partition 2 of disk 0 (disk0s2). It contains your currently running OS and user files. You do not want to delete it.

It seems to me that your SSD is not accessible at all, otherwise it would be disk1 and the synthesized disk would be disk2. But to be sure, show the full output from the diskutil list command.

In DiskUtility.app, select "View" -> "Show All Devices...". Do you see your SSD in the list of devices? Show a screenshot.

Hi, sadly even with "Show All Device" on Disk Utility the SSD isn't showing up.

I guess the SSD part of this Fusion Drive is most likely dead.

If you know a recommendation to revive the SSD, that'd be great, otherwise thank for the reply. I'll do my best to open the iMac up or use external SSD with a hub.

By the way why isn't disk 1 in disk 0 as disk0s5? I typed 'diskutil list' again, it looks like this:

 

[joevt]

disk0 and disk1 are separate entities even though the contents of disk1 are on disk0.

disk1 is like a virtual disk or a disk image. It's not a real disk. The contents of disk1 come from the contents of disk0s2 which has a special format for encoding the contents of disk1.

If you mounted a disk image, it would appear as a new disk. The contents of the disk would come the contents of the disk image file located on one of the other disks. The file has a special format for encoding the contents of the disk (it may be compressed or it may be a sparse image which means it only stores non-empty disk blocks).

APFS is interesting because although it shows 6 separate volumes in your case, they all share the same space of disk0s2 which means they can all be up to 1.4 TB in size. Any space not used by one volume can be used by another volume inside the same APFS container.

For the SSD, I suppose you could try putting it into an external enclosure if you really want to try to use it. OWC has upgrades for iMacs (and video instructions) that may include an external enclosure. Your SSD probably won't work even in an external enclosure. Or if it did, then it may mean your SSD connector is broken.
Go to www.macsales.com, click "My Upgrades", select your iMac model, select "Internal Drive Option" for internal drive upgrades. Select "External Storage" for external options (they have four options for Apple Blade-style SSDs (4) )

 

[Nermal]

Does the SSD show up in System Profiler under the NVMExpress or SATA sections?

 

[Alvin777]

Does the SSD show up in System Profiler under the NVMExpress or SATA sections?

Hi, sadly it doesn't. It says: "This computer doesn’t contain any NVMExpress devices. If you installed NVMExpress devices, make sure they are connected properly and powered on."

Does that mean the slot for the Apple SSD (it's version of M.2) is broken or just the Apple SSD?

Thanks.

 

[joevt]

Does that mean the slot for the Apple SSD (it's version of M.2) is broken or just the Apple SSD?

One or the other. Won't know until you try a different SSD. it's probably the SSD.