• MacBook Pro Mac16,7 (M4 Pro) running macOS 15.0.1 Sequoia (Build 24A348)
• Drive: OWC Aura Pro IV 2TB NVMe
• Enclosure: OWC Express 1M2 80Gb/s
• Also tested through: OWC Thunderbolt 5 Dock
• Purchased: September 11, 2025 (less than 30 days old)
• Backup software: Carbon Copy Cloner

During CCC backup operations (approximately 90 minutes in), the enclosure force-ejects with system error. macOS kernel logs show:
2025-10-06 23:52:01 kernel: (apfs) apfs_vfsop_unmount:3416: disk5s1 failed to finish all transactions before unmount! (err 6)
2025-10-06 23:52:02 kernel: (apfs) tx_unmount:1878: disk5 tx_finish() failed, 6

The kernel forcibly unmounted the drive due to I/O communication failure - the enclosure stopped responding to I/O requests.

SoftRAID Status:

This is NOT a SoftRAID issue. SoftRAID Monitor consistently reports:
✅ All SMART tests pass
✅ No disk failures detected
✅ Drive hardware is healthy

Most recent SMART test: Oct 6, 22:42 PM - just before the failure at 23:52 PM
Post-failure SMART test: Oct 7, 09:54 AM - still passing
The NVMe drive itself is fine; the enclosure's USB-C bridge chip or electronics appear to be failing under load.


Troubleshooting Done:
✅ Tested direct connection to MacBook Pro - failure occurs
✅ Tested through OWC Thunderbolt 5 Dock - failure occurs
✅ Multiple USB-C ports tested - failure consistent
✅ SMART diagnostics - all pass
✅ Different cables tested - no change
✅ Verified with system logs - clear I/O error 6

Technical Details:

USB Device Info (from System Information):Express 1M2 80G
Manufacturer: Other World Computing
USB Vendor ID: 0x1e91
USB Product ID: 0xde8a
Link Speed: 12 Mb/s

Error indicates:
The USB-C controller/bridge chip in the enclosure loses communication with macOS during sustained write operations. This is a hardware defect in the enclosure, not the NVMe drive.


Why I'm Posting Here:
OWC has no user forum for community troubleshooting
Others may encounter this with the new Express 1M2 enclosures
Documentation for warranty claim
Community might have insights or firmware updates I'm unaware of

Next Steps:
Contacting OWC support for warranty replacement. Will update this thread with their response and resolution.

Questions for the Community:
Has anyone else experienced I/O errors with OWC Express 1M2 enclosures?
Are there known firmware updates for this enclosure?
Any thermal management issues reported with these enclosures during extended writes?

Note to SoftRAID Users:
If you're using OWC Express 1M2 enclosures for backup operations, be aware this hardware issue exists. SoftRAID will correctly report the drive as healthy (because it is), but the enclosure may still fail during operations. This is an enclosure electronics issue, not detectable via SMART monitoring.


Helpful for others experiencing similar issues:
Check kernel logs: log show --predicate 'eventMessage contains "disk5"' --info --last 24h
Look for "failed to finish all transactions" errors
Verify SMART status with SoftRAID
Test multiple connection methods to isolate the issue

We posted a Critical Alert that applies to all SoftRAID users with NVMe or SSD based RAID 4 or 5 volumes.
https://software.owc.com/knowledge-base/softraid-for-mac-important-steps-to-protect-your-raid-4-5-volumes-with-ssds/

The jist of the Critical Alert is ALL impacted users need to upgrade to MacOS Sequoia if possible, and "Validate" your volumes to avoid a bug that could cause loss of data. We include full instructions, a helpful video, and a workaround if you are unable to upgrade MacOS to Sequoia.

Once you have upgraded to Sequoia AND validated your volumes, this issue will no longer affect you.

If you have a Thunderblade, 4M2 Accelsior or other flash based storage, using RAID 4 or RAID 5, please read this post and follow the steps indicated.

This issue DOES NOT AFFECT RAID 0, or any other RAID level.

This information was contained in the SoftRAID 8 release notes. We also wrote/posted a blog about this fix.
However, many users missed the release notes (and our Rocket Yard post), we feel that not enough users are aware of this issue and the fix.

Please post any questions below, we have made this a sticky post to help maximize exposure of this issue.

Given the severity of this problem, I would like to outline the actions your team should have taken and explain why they are essential in such a situation:

1. Proactive communication: Upon discovering the code error, your team should have immediately notified all customers of the potential risks associated with upgrading to version 7.01. Prompt communication would have allowed users to avoid the risks posed by the software update and given them the opportunity to postpone the upgrade until a fix was available.

2. Detailed instructions:  Your team should have provided clear and concise instructions on how to mitigate the risks presented by the code error, including steps to roll back to the previous version, if necessary, or alternative monitoring methods to ensure data integrity and hard drive health during the interim. 

3. Detailed, step-by-step instructions: When providing customers with a link to reinstall version 7.0, include clear and concise step-by-step instructions to ensure proper installation. By breaking down the process into easy-to-follow steps and highlighting potential pitfalls, you can minimize the risk of customers making mistakes during the installation process.

4.Provide video tutorials: Create video tutorials demonstrating the proper installation process and addressing common issues. Visual aids can be an effective way to ensure customers understand the steps and expectations during the rollback process.

5. Offer additional support: Encourage customers to contact your support team if they are unsure about any aspect of the rollback process. Providing responsive and helpful assistance can further reduce the likelihood of installation errors and demonstrate your commitment to customer satisfaction.

6. Transparent timeline: It is crucial to keep customers informed about the expected timeline for resolving the issue. Offering a transparent schedule for delivering a patch or updated version that addresses the code error demonstrates your commitment to customer satisfaction and maintaining trust.

7. Ongoing updates: Regular communication regarding the progress of the resolution, even if there is no immediate fix, is essential to ensure customers feel supported and informed throughout the process.

8. Create a comprehensive FAQ: Develop a comprehensive FAQ or knowledge base addressing common concerns and potential issues that customers may encounter during the rollback process. This resource can serve as a valuable reference for customers and help prevent improper installation of the software drivers.

9. Apology and reassurance: An official statement apologizing for the inconvenience and potential risks caused by the code error, as well as a reassurance that you are actively working on a solution, would help maintain customer confidence in your company and its products.

Ultimately, the responsibility lies with your team to ensure that customers have the necessary information and resources to address the issue at hand. By providing comprehensive instructions and support, you can minimize the risk of improper installation while prioritizing data protection and customer satisfaction. I hope that you will reconsider your position and take the necessary actions to rectify the issue, communicate with your customers, and provide the required guidance to ensure data safety.

In conclusion, addressing such a critical issue requires prompt, transparent, and empathetic communication with your customers. Ensuring that they are well-informed and provided with appropriate guidance to mitigate the risks associated with the code error is key to maintaining trust and confidence in your software and company.

I hope that you will take these concerns seriously and act accordingly to resolve the issue and strengthen your relationship with your customers.

I had to reinstall softraid (6.0.4) on my Mac (running 11.3.1). When I launched SR after the reinstall, I was asked if I want to share information with SR developers anonymously -- I chose not to and clicked "cancel." After that I got the aforementioned error. When I close SR and restart it and get the same error again and again. I deleted the app (dragged the folder to trash because I can't access the uninstall option in utilities) and reinstalled it and am still getting this error. Any idea how to get out of this error loop?

(I sent the message via support form on the website -- after submission I get a blank page with a https://webto.salesforce.com/servlet/servlet.WebToCase?encoding=UTF-8 URL displaying. Obviously, I can't reach support thru the app itself because all menus items are greyed out.)

Im using macos Catalina 10.15.7 and now Softraid 6.0.3. I have also tryed to go back to previous Softraid versions but didnt work.

Im starting to get a little desperate because im working in a big project in this rais and i need to fix this as soon as possible. PLEASE HELP!!!

I pressed ok, but the disk is unmount. Waited 3 hours, disk unmount.
How to mount my volume?

The idea is give everyone a chance to see what the current beta is, and new features added to each beta. We are going to start adding features to the SoftRAID beta versions now.

IMPORTANT NOTE: for M1 users.... Big Sur 11.2 blocks the SoftRAID driver. we were expecting a fix in 11.3 beta 2. However, it does not fix the problem, M1 computers can only run SoftRAID with 11.1. There are threads in the M1 section to discuss this.

I deleted a RAID5 (4x 8TB). The HDDs themselves where not formatted yet.

The volume doesn´t show up in the right volume display.

The HDDs show up in the left.

Any chance to recover the RAID as it was?