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OWC Thunderbay no longer mounting on macOS 10.13.6

New Member

I have an OWC Thuderday (15TB) that is no longer mounting to my system (macOS 10.13.6).


Not certain if a security update changed things, or downloading a trial of SoftRAID earlier this fall set things off, but it has been stable on High Sierra for the past several years. I have downloaded SoftRAID XT to try to diagnose the issue, but I am not able to solve the problem.

I have attempted several times to mount through SoftRAID, but no luck—it reverts to the unmounted state. Attached is a support file.

Topic starter Posted : 04/01/2021 10:02 am
Member Admin

I don't think the attachment made it, but a security update could block the driver.

If your volume does not mount in High Sierra (10.13.x) after updating the driver.

Diagnosis: Run SoftRAID. Look in the expanded volume tile for “Disk Identifier”. It should display a number, such as disk5. If this portion of the volume tile shows a “-“, then the SoftRAID driver is not loading.

Problem: The SoftRAID driver is being blocked from loading by High Sierra. This happens because a limited version of the SoftRAID driver is bundled with macOS, and we needed to change the Developer ID used with Apple to “notarize” OWC applications so that we could merge different accounts into one Developer ID.


There is a straightforward solution for 10.13, which works 100% of the time:

In summary we will ask you to:
Temporarily disable SIP (System Integrity Protection) Reinstall the SoftRAID driver
After all is working, re-enable SIP again.

Here are the steps:

Startup into internet recovery mode (hold keys command r at startup)

in terminal, paste in this command:

csrutil disable
then enter reboot into terminal, or restart from Apple menu.

After your system restarts:
Launch SoftRAID. Click on the volume tile for your startup volume. From the volumes menu "
Reinstall SoftRAID driver"

When the driver updates, the system needs to restart

Startup into internet recovery mode (hold keys command r at startup)

in terminal, enter this:

csrutil enable
then enter reboot into terminal, or restart from Apple menu.


Posted : 04/01/2021 1:58 pm
New Member



Hi... I am having a similar issue since updating to Softraid 6.0.3... I have split my OWC into 2 RAIDs... I get a report saying "MacOS can't repair STORAGE 1" but then recommends I copy all files from it and format it again... This is not good. Storage 2 then refuses to mount... even though I manually try mount it... Please could you assist with this?


Posted : 20/04/2021 4:54 am
Member Admin


Both volumes at once?

very unusual. the issue, from what I can tell, is caused when macOS shuts down faster than the drives can flush the last directory write out to disk, which causes gradual directory damage. This problem started when Apple moved to SSD instead of HDD as a startup volume, so my theory makes sense. And this has not been fixed to this day.


Disk Warrior is the best at rebuilding directories. it will be easy for the mounting volume, the other volume, the volume header looks OK, so it should not be a problem for Disk Warrior to repair.

I do not know of any other utility that can repair HFS volumes like Disk Warrior does.

Posted : 20/04/2021 9:49 am