This happened to me 2 days back. I reboot the NAS and everything worked fine. Today, I could not see any files on my 2nd drive. (I have setup RAID as JBOD). I checked under storage - volumes and raid management,it said could not mount drive. I reboot the NAS, and it show the files in that drive again. After few mintues, the 2nd drive could not be accessed at all.
did you acknowledge the message at the top before reboot NAS? i suppose there’s only 1 way to find out if the earx drive works and thats to pop it in. im concerned that if you had your drive set to JBOD…you have lost the data on the failed drive?!