Please help me remove a zombie slice from an APFS JBOD RAID

[karlfranz]

In my 5,1 mac pro, I have a Sonnet M.2 4x4 PCIe card with two 2TB nVME SSDs configured as a JBOD concatenated set that I use for storing VST audio libraries. I started running out of space so I just added a new 2TB drive. After rebooting, OSX (Mojave) ask me to initialize the drive and I used Drive Utility to add it as a slice to the JBOD set. After it was done, it reported there was an error. Even though the volume set now reported as 6TB, something didn’t seem right. I thought maybe I should have initialized the drive as APFS first prior to adding it to the set so I removed the slice and reformatted it. When I tried to add it back in, I noticed that the set reported it was missing a slice (the one I removed) and without it, the set won’t mount. I’ve tried remove this ‘zombie” slice with diskutil’s GUI and the command line, but it won’t let me. Since the new drive was reformatted, it was assigned a new UUID so it doesn’t recognize it as the missing slice.

Playing around with diskutil, I was able to add the new nVME drive as a slice, but now the set says it has Four slices including the previous zombie. The volume still won’t mount or let me remove the slice. So now I have:

• slice 0: 2TB full
• slice 1: 2TB almost full
• slice 2: zombie slice reported as missing/damaged
• slice 3: 2TB completely empty

Disk Utility only lets you remove the last slice and, no matter how I rearrange the blades on the card, the zombie never gets assigned the last slice and the volume never mounts.

Does anyone have any knowledge on how to fix this?

Here is what diskutil reports:

AppleRAID sets (1 found)
===============================================================================
Name:                 PCIe Storage
Unique ID:            78D78E3E-73E0-4F4E-8224-C573B133DA2E
Type:                 Concat
Status:               Offline
Size:                 6.0 TB (6000164831232 Bytes)
Rebuild:              manual
Device Node:          -
-------------------------------------------------------------------------------
#  DevNode   UUID                                  Status     Size
-------------------------------------------------------------------------------
0  disk0s2   AF7AD992-97C8-4A5E-B2C2-0E4AF006D779  Online     2000054943744
1  disk2s2   E39B5659-DDAE-4F76-8D51-0A0C9267CE4E  Online     2000054943744
-  -none-    8A90617A-2EFE-4E8E-8F88-F7E772228FDC  Missing/Damaged
3  disk1s2   26C52D06-A1A3-4462-9DD5-FBD06D74529E  Online     2000054943744
===============================================================================

 

[karlfranz]

Here is what I get when I try removing a slice:

dev karlfranz$ sudo diskutil appleRAID remove 8A90617A-2EFE-4E8E-8F88-F7E772228FDC 78D78E3E-73E0-4F4E-8224-C573B133DA2E
Started RAID operation
Can't remove members from this type of RAID set
Error: -69886: Invalid request

 

[ahodes]

Since slice 3 is completely empty, are you able to remove it? Once you do so, perhaps you can remove the zombie slice (slice 2)? If that doesn't work, you might need to recreate the set.

 

[karlfranz]

Since slice 3 is completely empty, are you able to remove it? Once you do so, perhaps you can remove the zombie slice (slice 2)? If that doesn't work, you might need to recreate the set.

I did try removing that nVME blade, removing others, changing the order they are mounted on the card, etc. but nothing has worked so far.

The most frustrating thing is that I know all my data is there. I haven't added or removed any files from the volume. The ONLY problem is that the JBOD is somehow convinced that there are now two more slices that it can't see. If I knew of a way to make it forget that those two extra slices exist, the drive would be able to mount exactly as before. I'm trying to see where the data about the configuration of a JBOD is stored in the file system, to see if there is another way to alter it, but I haven't come across anything yet.