Support suggested that I reset all settings.
I did and it did not fix everything but at least it was a good start.
Now, the original Pool reappeared but only one of the 3 original drives was randomly listed in Pooled, and the other two were listed in Non-pooled.
Trying to add these Non-Pooled drives would create some kind of "cannot add drives again" error.
In the end, I had to remove every Pooled drive from the "original pool" by restarting service, seeing a new random drive listed in Pooled, removing it and restarting service until all drives are removed from original pool.
Finally then I created a new pool, and moved all files from the original pool folders into the new pooled folders.
What a pain but it was not hard, at least I got all my files back without losing anything, which was shocking.
Please give me a like if this post has helped or will help anyone who run into similar issues.
Any hint in the gear icon in upper right -> Troubleshooting -> Service Log?
Check right after system restart and scroll to the very top, to see the part where DrivePool detects existing pools. (Maybe temporarily deactivate Service tracing / auto-scroll right after opening the log, to prevent the interesting lines to move out of view.)
And, just out of curiosity, are there any other pools shown in the UI? (click your pool's name in the top center in the main window)
And - also just another wild guess - are the two missing drives shown if you start your computer without the working drive plugged in? (Disclaimer: Do at your own risk. I'm just an ordinary user!)
DrivePoolfan got a reaction from Jonibhoni in Drives cannot be detected by DrivePool, how to get them to be detected?