PCIE M.2 drive not mounting after Sonoma install

I've been told Sonnet knows and has reproduced the bug, they have started a bug report with Apple. How long that takes to result in a rolled-out fix is anyone's guess. Better to stick with Ventura for now.

A recent update from Sonnet, confirming this is a bug caused by Apple and applies to multiple vendors:

Our engineers have been working hard on this and have now been able to reproduce the issue. Just recently we were able to duplicate this issue with competitor's hardware. From the data we have gathered from yourself and other customers, it does seem that an update released by Apple in the 2023 time frame for multiple OS' caused the issue with drives dropping off. We are trying to narrow down exactly which ones. We are in the process of filing a bug report to Apple so that they can get the issue fixed in a future OS release.

Seriously Apple, this is just embarassing.

If you're paying attention: FIX YOUR MAIN OS AND TEST THE BASICS BEFORE PUSHING OUT UPDATES.

I waited to install Sonoma in attempts to avoid compatibility issues. Just installed 14.3 and am consistently not seeing my drives that are on a Sonnet card. I restart a few times and they have reappeared and work fine.

To make things a little more confusing, I DID have this problem a couple of times on Ventura. Sonoma is worse, but this issue may have started earlier. I'm running a MacPro with three Samsung 2GB NVMe drives on a Sonnet card.

Same issue. @Apple -- I raised the same with enterprise support. We use NVME storage of sources | artifacts that need to be cached locally. We also test on 2019 MP (as you should) to ensure HW compatibility and every single one of our automations are failing on that hardware because of this issue.

This is absurd. They have no idea what they are doing. Forcing reinstalling the entire OS, twice, without analyzing what is going on is dumb. Replacing parts willy neely simply magic dreaming a fix and not investigating the actual issue sounds like something straight out of Idiocracy (the movie, look it up).

If you press Command-V during boot, you see the boot process in verbose mode on the screen. In my case, the system hangs initializing the GPU. That points a finger at how PCIe is being handled.

I've tried different NVME PCIe cards and all show the same issue. Once in a blue moon it boots fine and everything is there. Most of the time it boots and no drives are shown. Once in a while the entire system freezes during boot.

Can't point to a specific update where this started but when I first had the system (2019 and a couple of years after that) it all worked fine.

For anyone who wants to put in their own ticket with Apple about this issue — strength in numbers — Sonnet tech support wrote this to me:

If you would like, you can also try and submit your own Apple bug report, and reference the bug report we sent (FB13560165). More individuals reporting this may give more impetus to Apple to look into this more closely or more quickly.

We have also verified that, as a partial solution in the interim, installing the M.2 card/drives into an external Thunderbolt to PCIe chassis like our Breakaway Box, does resolve the issue of drives dropping off, albeit, bandwidth is limited to ~2800MB/s in the external chassis.

This just happened to me after I upgraded to Sonoma yesterday, I have 2 x Sonnet M.2 8x4 Silent Gen4 PCIe Cards. After restarting about 8 times they both showed up, I also turned off all background apps and any login at start up apps. Not sure if that was the trick but I will leave my system on until this gets figured out. I emailed Sonnet support hopefully they will have some solutions.

Hi, I thought I'd add my experience of this issue. MY Sonnet card doesnt show up in my 2019 Mac Pro either since the first Sonoma install. I'm now on 14.4.1 and it still doesn't show up. The Sonnet card has four Samsung nvME's installed, and worked perfectly before Sonoma.

I also have the OWC accelsior M4 card installed, with four WD NVME's installed, and that one shows up every time with Sonoma.

I've been in touch with Sonnet who are aware, and were disappinted that Apple didnt fix the issue in the 14.4.1 update.

Tony

For the record, I have the issue with both cards. This is not unique to Sonnet.

Tonse wrote:

Hi, I thought I'd add my experience of this issue. MY Sonnet card doesnt show up in my 2019 Mac Pro either since the first Sonoma install. I'm now on 14.4.1 and it still doesn't show up. The Sonnet card has four Samsung nvME's installed, and worked perfectly before Sonoma.

I also have the OWC accelsior M4 card installed, with four WD NVME's installed, and that one shows up every time with Sonoma.

I've been in touch with Sonnet who are aware, and were disappinted that Apple didnt fix the issue in the 14.4.1 update.

Tony

macOS 14.5: no change. In fact, after finishing the update, my 2019 Mac Pro came up with only one of my Sonnet M.2 4x4 PCIe cards. Cold power cycle, still came up with only one of them. Immediate reboot after that came up with both.

Can't fix it or won't fix it, seems the same answer either way.

OK, given I just "downgraded" (upgraded?) from Sonoma to Ventura, I can provide some pointers, but if you screw up your machine it's not my fault.

IMPORTANT: THIS WILL WIPE ALL DATA!!! Make sure you have a backup.

0) Backup your data. Maybe do this twice. I was able to find a Time Machine backup from before Sonoma was installed, but it should theoretically work if you have a Time Machine backup taken after Sonoma was installed. The way you will reinstall your files and apps is using Migration Assistant to read your Time Machine backup off an external drive (because Time Machine no longer backs up the OS, like it used to, or a full image backup would). Put your Time Machine Backup on an external drive.

1) You also need a bootable disk containing Ventura. Download Ventura from the App Store using this link. Despite your mac telling you it cannot install Ventura, the downloaded file you require will be put into your Applications folder: How to download and install macOS - Apple Support

2) Grab a USB drive with at least 16GB and follow these instructions to create the bootable Ventura installer using the file in your Applications folder: Create a bootable installer - Apple Support. The terminal command you need is something like: sudo /Applications/Install\ macOS\ Ventura.app/Contents/Resources/createinstallmedia --volume /Volumes/MyVolume

3) You need to enable the ability to boot from an external drive, using Recovery Mode to do this. Follow these instructions: About Startup Security Utility on a Mac with the Apple T2 Security Chip - Apple Support

4) Shutdown your Mac and remove all external drives except the bootable Ventura USB drive.

5) Restart and immediately hold down the OPTION key until Startup Manager appears. Choose your USB drive.

6) Choose Disk Utility -> View -> View ALL attached Drives. Choose the upper-most drive (not the indented volumes below). It's normally called Apple Media, Mac SSD, or similar. Erase this drive and format as APFS with a GUID Partition Map. If you use Bootcamp, leave that partition alone. I was able to leave my Bootcamp install untouched and it works just as it always did after installing Ventura.

7) Once your main Mac drive is wiped, exit Drive Utility and go back to the menu, then choose Install MacOS.

8) Start the installation of Ventura and follow prompts, but don't create an account (as in, don't enter any user details). If you enter new user details, you may end up with permission problems after restoring with Migration Assistant, even if it's the same username you used previously.

9) Open Migration Assistant when provided the option, select the Time Machine backup you saved to an external drive after plugging it in, start the restore process.

10) Migration Assistant seems to do a good job of restoring preferences, passwords, etc. It's honestly not that much of a headache to get everything going again after Migration Assistant completes.

Good luck and I take no responsibility for the above instructions.

On my MacPro 2019 running Sonoma, I tried an SMC restart and my drives reappeared. Don't know if this is just luck or a thing and don't know if they will continue to mount when I shut down ..

Reset the SMC of your Mac - Apple Support

I went to Feedback - Mac Pro - Apple and submitted my "Bug Report" for this issue. It neither gave me a ticket nor emailed me one, but at least my report is in. I encourage others to do the same and reference the bug report FB13560165 submitted by Sonnet.

Options that I've discovered to not keep waiting on Apple:

• move my two Sonnet PCIe cards to external Thunderbolt PCIe chassis
  • Sonnet eGPU Breakaway Box 750 (option recommended by Sonnet; pair for RAID 1)
  • Sonnet Echo I (option recommended by Sonnet; pair for RAID 1)
  • Sonnet Echo II DV (seems like a nice, if pricey, option if you don't strictly need separate chassis for your RAID 1)
• move my NVMe storage to external Thunderbolt NVMe chassis
  • Sonnet Echo Dual NVMe Thunderbolt Dock (plus buying higher capacity NVMe; pair for RAID 1)
  • OWC Envoy Pro SX (plus buying higher capacity NVMe; pair for RAID 1)
  • OWC Express 4M2 (repurpose my existing NVMe storage; pair for RAID 1)
• Vacate macOS and move to Linux or Windows (expensive option for cost and time, but at least it's end-game)

You lose 16x PCIe storage bandwidth with the move to 4x Thunderbolt bandwidth, but it's likely not a showstopper for me.