So, I will try to keep it brief, but also provide all of the info because I am now on day 3 of reading through forums and trying to repair the issue.

I had a drive (drive 8) finally fail on me. I decided to get 10 brand new 6TB WD drives, Merry Christmas to myself. I removed the failed drive, inserted the new drive and let the parity begin to rebuild the new 6TB drive. Since I wanted to make sure this drive was fully restored, I did not worry about the other couple drives with SMART errors until after this one rebuilt. The rebuild of this one drive was taking a long time (like we were on day 4 of it rebuilding) but I let it go because it was still moving along and I was not in any hurry for it to finish. On day 4, there was a power outage during the rebuild. I of course, have yet to get a UPS (yes I know, I know..). When I rebooted the system everything looked ok, but when I tried to start the array the disk were stuck "mounting" for several hours. I tried to soft reboot, but after clicking the button nothing ever happened so I had to hard restart it. This time, to keep it short, the flash drive was bad. Thankfully, I was able to pull the /config and create a new flash drive, however, that did not solve my issues with the system never actually mounting the drives. It still was stuck "mounting" the drives for hours.

I, like most people, would love to not lose the TBs of data in this media server. And have scoured the forums. I have found similar issues and tried those suggestions, but I am still stuck. Please help this is day 3 of trying things without breaking it more.

jarvis-diagnostics-20260107-2153.zip syslog.txt

The syslog doesn't show the mount; try copyon after you click start:

cp /var/log/syslog /boot/syslog.txt

When I click start it still gets stuck mounting drives and then I'm not able to pull the syslog. It's like it locks me out completely. I had to hard reboot and pulled some new logs (attached). The only thing that was different this time was that the cache and VM pools were missing disks and were showing not mounted. I was able to mount them. After the hard reboot, the drives were showing back correctly in their pools.

jarvis-diagnostics-20260108-1957.zip syslog20250108.txt jarvis-syslog-20260109-0206.zip

Edited January 9Jan 9 by WubbaLubbaDubDub

UPDATE: And possible solution. After more troubleshooting and just trying things, I could not get the array to start using the "Start" button. I was, however, able to put it in maintenance mode (which i was not able to do before and i believe that was an issue related to my failing USB) and then sync to begin the data rebuild. As the array was not actually started, I am not sure if this is fixed yet. I will return when the data is rebuilt with an update as to whether this solves the issue.

Maintenance mode doesn't mount any disks

5 hours ago, WubbaLubbaDubDub said:

When I click start it still gets stuck mounting drives and then I'm not able to pull the syslog. It's like it locks me out completely.

Enable the syslog server to save to the flash drive, then post that after a mount attempt.

5 hours ago, trurl said:

Maintenance mode doesn't mount any disks

Correct. However, the data is actually being rebuilt now which was also not occurring before. The hope is that once the data is rebuilt, the disks will mount. This has become a one thing at a time kind of process.

3 hours ago, JorgeB said:

Enable the syslog server to save to the flash drive, then post that after a mount attempt.

Too easy, I will do that right after the data rebuild completes and post. About halfway there now.

It has been a couple more days now. Looks like the solution was simpler than expected. For those who may encounter a similar issue in the future:

After restarting the server and placing it in maintenance mode, it allowed Data Rebuild to begin. I let this complete. Before taking it out of maintenance mode, I ran a Parity Check just in case. I then restarted the server and started the array. It has now finally started, and everything is working properly. Thank you, @JorgeB , for your assistance and for pointing out the syslog server option that I was previously unaware of. I now have my logs being collected on another server, just in case.

Edited January 10Jan 10 by WubbaLubbaDubDub

Just be aware that if you can't mount disks but you rebuild anyway, you may be rebuilding an unmountable filesystem. In that case we recommend rebuilding to a new disk and keep the original as is in case it might be useful in recovering data.

You don't mention whether your "just in case" parity check was correcting. Correcting parity might also introduce problems since the sync errors might be elsewhere.

Ah understood. Thank you for clarifying. Unfortunately, in my case, the drive that was being replaced was dead. I do have a couple more to replace so I will keep the old drives for a while in the event I need to recover from them.

I was initially hesitant about running the parity check for that exact reason you listed of introducing errors. If the data were more important, I would recommend verifying or correcting errors before doing the parity check. In this case, the data being recovered is on my media server. The importance of the server running in my specific situation was more crucial to me than the need to repair or remove bad data later. I am now performing scans and log checks to identify any potentially damaged data.

Thank you @trurl for mentioning those key points.