Hard drive not accessible, but works according to Disk Utility

[Poki]

Please help, this is driving me crazy.

I recently bought a WD My Book Thunderbolt Duo 8TB (software RAID 1 mirrored, 2 x 4 TB WD Red drives) to use with my Mac Mini (OS X 10.11.1). Until last Friday, the setup worked well as expected. But suddenly, the Finder didn't show the drive anymore and iTunes, Capture One and other software couldn't access it either.

In disk utility, the drives show up three times due to them being in a software RAID configuration (so it shows each drive once, the RAID itself once and the RAID mirror system once). When clicking on "First Aid", it tells me everything is okay. WD Drive Utilities itself says everything is okay, from the SMART status to a complete disk check.

The RAID monitoring in Drive Utilities tells me both disks as well as the RAID system are all online and working. The enclosure seems to work well too, since the LED flashes correctly when doing a drive test and the Thunderbolt port on the back correctly transmits the signal to my Thunderbolt Display.

The only sign that something is wrong is when I restart my Mac, I get an error message stating "The inserted medium could not be read by this computer."

When scanning the drive with Any Data Recovery, it indeed is able to find every single file, so the data still must be there.

Also, Apple Hardware diagnostics did not return any error with my Mac Mini. Using the "diskutil list" command, Terminal correctly shows both hard drives in the RAID enclosure as well as the mirrored RAID itself. Using "ls /volumes", the Thunderbolt Duo does not appear, however.

Any ideas what is happening and how I can fix it?

 

[Poki]

I tried two more things in the meantime: Using kext utility to check if there's something wrong (there isn't), and I tried removing one of the hard drives, putting it into an USB enclosure and connecting it to my old MacBook -- it behaves exactly the same in this configuration (i.e. not showing up in Finder, but showing up twice in disk utility).

Now the disk is reporting that the RAID is being rebuilt, probably because some Spotlight data were written on the disk when it was connected to my MacBook and now it thinks something is corrupted ...

Whatever, still not any closer to a solution. Any more ideas?

 

[Poki]

Something interesting: When trying to mount the disks using Terminal, it tells me they mount successfully ... How can this be when the disks are not showing in Finder? Here's the code:


Mac-Mini:Volumes hannesbrecher$ diskutil list

/dev/disk0 (internal, physical):

#: TYPE NAME SIZE IDENTIFIER

0: GUID_partition_scheme *250.1 GB disk0

1: EFI EFI 209.7 MB disk0s1

2: Apple_HFS Macintosh HD 249.2 GB disk0s2

3: Apple_Boot Recovery HD 650.0 MB disk0s3

/dev/disk1 (external, physical):

#: TYPE NAME SIZE IDENTIFIER

0: GUID_partition_scheme *4.0 TB disk1

1: EFI EFI 209.7 MB disk1s1

2: Apple_RAID 4.0 TB disk1s2

3: Apple_Boot Boot OS X 134.2 MB disk1s3

/dev/disk2 (external, physical):

#: TYPE NAME SIZE IDENTIFIER

0: GUID_partition_scheme *4.0 TB disk2

1: EFI EFI 209.7 MB disk2s1

2: Apple_RAID 4.0 TB disk2s2

3: Apple_Boot Boot OS X 134.2 MB disk2s3

/dev/disk3 (external, physical):

#: TYPE NAME SIZE IDENTIFIER

0: GUID_partition_scheme *1.0 TB disk3

1: EFI EFI 209.7 MB disk3s1

2: Apple_HFS Backup Drive 999.9 GB disk3s2

/dev/disk4 (external, physical):

#: TYPE NAME SIZE IDENTIFIER

0: GUID_partition_scheme *2.0 TB disk4

1: EFI EFI 209.7 MB disk4s1

2: Apple_HFS WD My Book 2.0 TB disk4s2

/dev/disk5 (external, virtual):

#: TYPE NAME SIZE IDENTIFIER

0: Apple_HFS +4.0 TB disk5

Mac-Mini:Volumes hannesbrecher$ diskutil mountDisk disk2

Volume(s) mounted successfully

Mac-Mini:Volumes hannesbrecher$ diskutil mountDisk disk1

Volume(s) mounted successfully

Mac-Mini:Volumes hannesbrecher$ diskutil mountDisk disk1s2

Volume(s) mounted successfully

Mac-Mini:Volumes hannesbrecher$ diskutil mountDisk disk5

Volume(s) mounted successfully

Mac-Mini:Volumes hannesbrecher$

 

[Poki]

As an update: I solved the problem, but I still don't know what caused it.

How did I solve it? I copied all files from the RAID to another disk using Wondershare Data Recovery and then reformatted the WD My Book Thunderbolt Duo as HFS+ RAID1 using WD Drive Utilities. Now it mounts again ... But as this process takes up to 36 hours (24 hours for the data recovery + 12 hours for the data transfer), I'm not too keen on doing it again and again in the future, so if somebody has any idea what caused this issue, please share your wisdom with me.

 

[ColdCase]

On rare occasions (one) I've had a drive not show up in the finder directly, but show up under the computer. That is, in the finder double click on the computer and the drive is listed there, along with all the other mounted volumes. In other words, the drive is mounted but not at the "top" level.

I dunno how that happens or how to fix it...

 

[Poki]

On rare occasions (one) I've had a drive not show up in the finder directly, but show up under the computer. That is, in the finder double click on the computer and the drive is listed there, along with all the other mounted volumes. In other words, the drive is mounted but not at the "top" level.

I dunno how that happens or how to fix it...

Wasn't my problem, unfortunately - disk utility did show it was NOT mounted, even though Terminal told me it mounts correctly.

 

[ColdCase]

Was the drive encrypted by any chance?

 

[Poki]

Was the drive encrypted by any chance?

Since it worked the day before and suddenly stopped working without me doing anything, I wouldn't know how this could have been the case. Maybe malware of some kind which suddenly encrypted the drive? That may be a possible answer, but it seems a little far-fetched tbh. Also, shouldn't there be some way to tell whether a drive is encrypted?