I was having a problem with my 2TB green drives and the head cycle count, so I started pulling out drives out of my pool, and replacing them with a spare, one at a time, so I could remove the timer in the firmware.
The first one removed no problem, drivepool removed the data from the drive, I put in a new 3TB red, and added it to the pool. No issues.
A couple of days later, I do the same thing, but I put in the green I pulled out. This time though, when I rebooted the server, errors started popping up, and the drive pool had changed from F: to L:, so all my shares disappeared, including my N