Depending on the history of your Fusion Drive the following diskutil list
result:
diskutil list
/dev/disk0
#: TYPE NAME SIZE IDENTIFIER
0: GUID_partition_scheme *120.0 GB disk0
1: EFI 209.7 MB disk0s1
2: Apple_HFS SSD 119.7 GB disk0s2
3: Apple_Boot Boot OS X 134.2 MB disk0s3
/dev/disk1
#: TYPE NAME SIZE IDENTIFIER
0: GUID_partition_scheme *3.0 TB disk1
1: EFI 209.7 MB disk1s1
2: Apple_CoreStorage 3.0 TB disk1s2
3: Apple_Boot Recovery HD 650.0 MB disk1s3
usually indicates that the CoreStorage Logical Volume Group got corrupted or a Logical Volume is missing. Otherwise you would have an additional disk:
/dev/disk2
#: TYPE NAME SIZE IDENTIFIER
0: Apple_HFS HDD *3.0 TB disk2
Logical Volume on disk1s2
F7C46A1C-6701-4115-AEA3-C55106875F1D
Unencrypted
In case of a corruption entering diskutil cs list
reveals something like this then:
diskutil cs list
CoreStorage logical volume groups (1 found)
|
+-- Logical Volume Group 3A3D2012-091B-4C5B-A245-EC6EDF098AFE
=========================================================
Name: HDD
Status: Initializing
Size: 2999174897664 B (3.0 TB)
Free Space: -none-
|
+-< Physical Volume ADB774DB-13DA-4644-BC02-E447E49150F8
| ----------------------------------------------------
| Index: 0
| Disk: disk1s2
| Status: Checking
| Size: 2999174897664 B (3.0 TB)
|
+-< Physical Volume 5EE639D1-D69D-4110-B01E-7A8E11CEE18A
----------------------------------------------------
(No properties)
In this case neither removing a/the missing Physical Volume with diskutil cs removeDisk pvUUID
(with pvUUID: UUID of the missing Physical Volume) nor deleting the Logical Volume Group with diskutil cs remove lvgUUID
help.
All content of the volumes will be erased. So backup or save any available data first.
You have to remove the whole partition with
diskutil umountDisk /dev/disk1
sudo gpt -r show /dev/disk1
sudo gpt remove -i 2 /dev/disk1
and re-add it with
sudo gpt -r show /dev/disk1
sudo gpt add -b StartBlock -i 2 -s size -t 48465300-0000-11AA-AA11-00306543ECAC disk1
in the empty space of disk1
Example:
sudo gpt -r show /dev/disk1
start size index contents
0 1 PMBR
1 1 Pri GPT header
2 32 Pri GPT table
34 6
40 409600 1 GPT part - C12A7328-F81F-11D2-BA4B-00A0C93EC93B
409640 5857763472
5858173112 1269536 3 GPT part - 426F6F74-0000-11AA-AA11-00306543ECAC
5859442648 7
5859442655 32 Sec GPT table
5859442687 1 Sec GPT header
Re-add the partition:
sudo gpt add -b 409640 -i 2 -s 5857763472 -t 48465300-0000-11AA-AA11-00306543ECAC /dev/disk1
Unmount the disk and create a new file system:
diskutil umountDisk /dev/disk1
sudo newfs_hfs -v "HDD" -J /dev/disk1s2
Verify (and repair if necessary) the disks and the volumes:
diskutil verifyDisk disk0
diskutil verifyDisk disk1
diskutil repairDisk disk0
diskutil repairDisk disk1
diskutil verifyVolume disk0s2
diskutil verifyVolume disk1s2
diskutil repairVolume disk0s2
diskutil repairVolume disk1s2
Now you should be able to continue recreating a Fusion Disk:
diskutil cs create disk0s2 disk1s2
diskutil cs addVolume lvgUUID jhfs+ "Macintosh HD" 100% #lvgUUID: the UUID you got in the previous step
This might fail if one or both of the disks are physically corrupted.