Internal PCIe SSD drives not mounting in 2019 Mac Pro with Sequoia 15.2

RHeidel wrote:

I have a Mac Pro 2019. This issue started after updating to Sonoma and has been a nightmare ever since. The problem persists in Sequoia 15.2.

I have two OWC Accelsior 4m2 PCIe drives, both formatted using AppleRAID in a RAID0 configuration. Only one of the drives will mount reliably at a time. It takes around 20-25 restarts for both drives to mount, so, it is in fact possible for both of them to mount.

First Aid in Disk Utility indicates that both drives are healthy and error-free. Both are formatted in RAID0 using AppleRaid.

I have already taken the computer to an Apple Authorized service center and they determined that there is neither a problem with the Mac hardware, nor a problem with drives themselves.

I have already raised this issue with OWC and they are well aware of the problem. They confirmed that this is a problem with Apple’s software, and that there is nothing they can do on their end.

Both drives mounted reliably, every time, in Ventura. This machine is my daily driver and I can’t afford to have my $12,000 Mac Pro to be unusable after only a few years. Please help.

your macOS is current —stable release of Sequoia including bug fixes, security updates is macOS 15.2

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