PCIE M.2 drive not mounting after Sonoma install

+1. Same issue with Sonnet drives on my 2019 Mac Pro.

2019 Mac Pro, same issue. had machine checked by Apple, all good. All since Sonoma update. I've even bought a new card thinking it was that, but the same issue. Sometimes only mounts 2 of my 4 SSDs. Anybody with any fixes?

I have a 2019 Mac Pro and am also seeing this issue with a number of my internally mounted M.2 SSDs.

It has gotten to the point where I need to boot the computer then shutdown and unplug it then restart.

Exact same issue here. Sonnet M.2 Pcie card in 2019 Mac Pro randomly doesn't mount on system restart since updating to Sonoma. I can't find any consistent pattern to it.

Exact same problem! Everything was fine on Ventura with 2019 Mac Pro. Now after a (forced) Sonoma 'upgrade', often random NVME M.2 drives installed on my 2 Sonnet 4x4 M.2 PCIe cards will not mount after booting. Nothing else has changed. It's like the lottery whether after booting, a drive is just missing and not showing in Disk Utility. If the drive shows up later, the RAID array works fine. It's not a disk or driver issue, it's Sonoma 100%. Please fix this Apple!

Same here, any news on a fix ?

As a test I 'downgraded' from Sonoma to Ventura, using Migration Assistant to restore all apps and files exactly the same as before, with exactly same hardware configuration, and now all M.2 NVME drives installed on both Sonnet 4x4 PCIe cards mount perfectly on my Mac Pro 2019, everytime.

Apple, what on earth have you done with Sonoma to cause external drive mounting to become a random lottery??

+1

4 years running 4 x NVME sticks (RAID 0) with no issues. Now (after Sonoma), they show up only after several power cycles. No rhyme or reason as to the number of power cycles. Once they come up upon boot, they work fine for the duration. Went through everything under the sun trying to solve it until I found this thread and realized I'm not on my own. (RaidCP is a spinner used for backup)

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.

I am having trouble downgrading to Ventura , do I need to erase the disk first and then restore a Time Machine backup ?

2019 Mac Pro, 192GB, 1TB SSD and 5700 MPX.

I am also having this issue since installing Sonoma. Most times I need to shut the computer down and unplug the box. After doing this a few times the drives appear. The drives are Samsung 970s mounted on PCI adapter cards.

There are no RAID partitions configured.

I have gone through each step mentioned in this thread and the related MacRumors thread.

https://forums.macrumors.com/threads/mac-pro-2019-nvme-raid-drives-failing-to-mount.2366297/

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.

Thanks for taking the time to explain, very helpful !