Pegasus2 R4 - DISK NOT EJECTED PROPERLY Issue with macOS 11.3

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Robert Bousfield posted this 2 weeks ago

Mac Pro 2013 / macOS Big Sur 11.3 / Promise Pegasus2 R4


After upgrading to macOS Big Sur 11.3 I am notified that the two volumes on my Promise RAID are disconnected when my Mac wakes from sleep.



Console log shows the Mac thinks the cable has been disconnected - it hasn't and same cable was working fine with macOS 11.2.3


default    19:51:20.253087+0100    kernel    STEX : Thunderbolt cable disconnected while wake up


I also tried a new Thunderbolt 2 cable - same issue.


Anyone else seeing this behaviour?








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Jan Vercammen posted this 1 weeks ago

Dear Robert,

I too see this kind of behaviour on my Mac Pro late 2013 with Pegasus2 R4 after Big Sur 11.3. 

  • Put Mac to sleep
  • After a while the R4 turns off
  • Shortly later R4 turns back on - does something ??? - then turns back off  (did not happen before 11.3)
  • Wake up with spacebar

Resulting in 2 of those messages.

Kind regards,


Felix Sorger posted this 6 days ago

Hi Robert and Jan,

I am having the exact same problem and same behaviour as described by Robert. It actually really disconnets because FCPX exits because it cannot (could not) read/access the open Library anymore.

Kind regards,




Latest Software Promise Utility and Firmware

Pegasus2 R4

Big Sur 11.3, Mac Mini 2018, 3.2 i7, 32GB RAM with EGPU BM Radeon Pro 580

Robert Bousfield posted this 3 days ago

Hi Jan/Felix,

Many thanks for taking the time to also report you are also seeing the same behaviour.

I have raised a support ticket with Apple about this.

The problem is still present in the macOS 11.3.1 update released last night  - which I understand was a primarily a security patch so I did not expect any change in this behaviour but one always hopes 😉



William Wood posted this yesterday

Same problem here...

Mac Pro late 2013 with Pegasus2 R4 after Big Sur 11.3 and with 11.3.1.