Hi there, problem solved: the culprit was an older disk I had used as a temporary backup and apparently in some way interfered with the SoftRAID volum...

I agree ;-) What component could that be, as it never occurred before the system reinstall … Something that might point to the culprit: Before re...

Alas, that didn't help. And it happens every time when waking from sleep … Any other suggestion? Thanks, Han

Did you try updating the firmware ? This only works on Thunderbolt 3 versions of the OWC Thunderbay, though, for when one or two disks eject. Wh...

Unmounting needed some extra effort, but ultimately succeeded. Resizing succesful! Thanks for your help :-)

Is 'First Aid' necessary? It can't unmount the disk set, closed all open apps, except Finder and obviously Disk Utility … (see screenshot)

So first Apple's Disk Utility and then SoftRAID's 'Resize Volume'? (as I don't see an 'Expand Volume' command).

I indeed think I expanded it by replacing disks.

Hi SR supporter ;-) Thanks for answering. Saw it only just, apparently missed the e-mail notification. It seems that one of the old disks (that I mo...