JonathanM

That doesn't give me the warm'n'fuzzies about your PSU. If it were me I'd replace the PSU and all power cabling before powering up the system. Hate for whatever happened to repeat itself with finality.

Unfortunately anything you generate now probably wouldn't be very helpful. I was hoping that maybe you had downloaded the diagnostics zip file prior to everything falling apart. If you boot the server, and don't attempt to start the array, you should still be able to go to tools, diagnostics, and download the diagnostics zip file as things currently stand. Do you at least have a full copy of the screenshot you posted in the first post? You truncated the serial numbers, which are the important parts to identifying which drives were assigned to the slots.

Is the repair shop aware that you need bit perfect copies of the drives and not just the files? If not, they may be writing off your parity drive as failed since it has no files. If you can get three out of 4 drives bit perfect, you are golden, as you can emulate the remaining drive. The good news is each data drive is independent, so if they recover 2 data drives, you will have those files. Do you have any diagnostic files from before the failure? They would contain helpful information.

That's not a supported version, 6.8.3 is the oldest version actively supported. If there is something in 6.8.3 that doesn't work with your setup, try the latest 6.9 release candidate. It's not a good idea to stay with that old of a release anyway, there are vulnerabilities that are fixed in the newest versions, and you will need to eventually go to the 6.9 series anyway, so if there is some incompatibility with the current 6.9 release candidate with your setup it would be good to get that addressed with limetech before the 6.9 release. That's not going to happen, for the reasons I just stated.

Yeah, that's running very close to the minimum for what you are trying to do. If you can, I'd advise 16GB to give you some breathing room. It will help everything be a little more snappy.

Yes, plug the USB stick into your desktop.

Settings, Global Share Settings.

I recommend backing up all the files on the USB stick to a desktop, then run the USB creator tool and install the latest version. Find the plus.key file in your backup and copy it to the config folder on the newly prepared USB, then boot up and see what you get.

As long as the first drive is BTRFS, yes. If you don't change any options, you will end up with 500GB of storage capacity after adding the 1TB, but it will be redundant. See https://carfax.org.uk/btrfs-usage/ for what you can expect with various mixes of drives and RAID types.

That's what should happen if you follow the parity swap correctly. You can still manually copy the emulated content of the 3TB to another location (preferably not on any of the other array disks) before you start the full procedure if you wish.

That should work, but seems awfully convoluted. Since you don't care about parity until you are done, why not... 1. Shut down. 2. Do the drive dance, physically put ALL the drives where you eventually want them, the existing drive with data can be connected to any physical location. 3. New Config, assign final drive 1 in first data slot, assign existing data drive to second data slot, don't assign anything else. Make sure only disk1 is unformatted, let it format. 4. COPY data from drive 2 to drive 1. That way you have a backup. 5. Shut down. 6. Remove 4TB 7. Power up, new config, assign everything where it goes, build parity. That way you limit the number of times you are physically and logically reassigning drives.

Is your cache pool a single device or a BTRFS RAID?

Parity doesn't work that way, it has no information about individual files, only entire drives. The 3TB drive showing as emulated is what parity is doing, it emulates missing drives so you can access the data on them, or rebuild to a new drive. That's what the parity swap procedure I posted is for.

If by that you mean rebuild without the data from the 3TB, then yes, that's exactly what will happen.

https://wiki.unraid.net/The_parity_swap_procedure

Have you backed up the data that is on the emulated 3TB? If you do a new config, all data that was on that drive will be irretrievably erased.

Keep in mind that whatever caused your BTRFS issues may still effect your data, but you may not find out immediately. BTRFS is, as I like to put it, fragile. BTRFS will reveal issues in a much more dramatic way, and doesn't seem to be as recoverable as XFS, but that doesn't mean your issues were CAUSED by BTRFS. A stable well running system should have no problems with BTRFS. So beware of masking an issue vs fixing the actual problem, be it flaky RAM, power, whatever.

You already told us the motherboard sees the card. That's what the PIKE card is.

This unraid specific tool (script) isn't meant specifically to do what you ask, but it could possibly work, depending on what the issue is. newperms <full folder path>

Not that I'm aware of. Unraid replaces the mdadm functionality with its proprietary array software.

Post a screenshot showing what you mean. It's exactly the same in 6.8 and 6.9 for me.

I understand exactly what you are trying to do, unfortunately I don't think it's going to work the way you want it to, because I doubt the LTS repository is going to land on any of the currently available 6.x builds, there are just too many issues right now. The best you can hope to do is put in the tag of the image you are currently using instead of latest, and keep watching as things progress until there is a later version that you deem to be worth trying to update. Look on the docker hub page linked in the first post at the tags tab, there you will find the current list of available images.

Try starting the array with NO cache devices assigned at all, then reassign them back to their original slots.

My view is... Plex is dependant on an internet connection, and has a symbiotic relationship with the plex company's resources for normal everyday tasks. Emby is local, and doesn't need to communicate with the emby company except to verify license for some features. I can still use Emby even if my internet is down.