Performing a factory reset on your M1 Mac to regain access to your SoftRAID volumes

Author: OWC Tim
posted on Feb. 08, 2021

Last week we alerted you to a critical issue with macOS Big Sur 11.2 which makes SoftRAID volumes inaccessible on M1 Macs. We warned you not to update your M1 Macs until Apple released a fix for this problem and recommended that if you already had updated and needed to revert to macOS 11.1, the best route was to restore your most recent Time Machine backup.

If you do not have a Time Machine backup, I recommend using an Intel Mac with your SoftRAID volumes until Apple fixes the problem. If this is not an option for you, my final suggestion is to perform a factory reset on your M1 Mac.

There are many other situations where you might have to perform a factory reset on an M1 Mac. During our 6+ months of testing, we have had to perform this factory reset four times (and we only have five of the M1 Macs). The problems we have fixed this way include things like M1 Macs no longer booting and M1 Macs losing all network access.

Performing a factory reset is truly the last recourse, but it is what I recommend when there is no other option.

Resetting Your M1 Mac Using DFU Mode

Important: Resetting your M1 Mac using DFU (Device Firmware Update) will delete ALL your files on ALL internal volumes on your Mac. This is a real, true, factory reset. We recommend you perform a full backup and disconnect all external storage before performing the DFU restore.

You will need a second Mac to perform the factory reset operation. This second Mac, which I will call the Rescue Mac, can be any Thunderbolt 3 or USB-C equipped Mac running Big Sur.

1. Download the IPSW firmware file for macOS version 11.1 from Apple’s CDN onto the Rescue Mac.
2, On your Rescue Mac, go to the App Store and download  Configurator 2.
3. Make sure your M1 is shutdown. If it is a Mac mini, unplug it!!!
4. Connect your Rescue Mac to the M1 Mac.

Note – you must use the following Thunderbolt port on your M1 Mac or the factory reset won’t work:

MacBook Pro & Air: left rear connection

Mac mini: left most connection, next to Ethernet port

5. On the Rescue Mac, run the Configurator 2 application. The main screen will be blank.
6. Enter the DFU mode on the M1 Mac (watch this YouTube video for help on how to do this) … timing is important!
MacBook Pro or Air: Hold down the power button, right shift, left option, and left control for EXACTLY 10 seconds, then release all keys except power for 7 seconds. You will see DFU appear on the host computer.
Mac mini: Hold down the power button, and THEN plug in the cable. Continue holding the power button until you see DFU appear on the host machine.
7. Now that your M1 is in DFU mode and shows up in Apple Configurator, drag the downloaded IPSW file from Step 1 into the DFU window.
8. Configurator will start to install the file onto your M1 and should only take about 15-30 minutes to complete.
9. When finished, disconnect and restart your M1 – it will startup to the initial boot screen.

macOS 11.3 and SoftRAID Email Alerts

We anticipate that Apple will release macOS 11.3 very soon and expect that this will fix the issue that prevents access to SoftRAID volumes. In the meantime, we hope that these temporary fixes will be helpful. We also encourage you to stay informed by signing up to receive SoftRAID Critical Updates via email. We will send out a SoftRAID Critical Update email and update this blog post as soon as we have more info about Apple’s progress in fixing this macOS bug.