JorgeB

I assume it's not always the same disk?

It's not logged as a disk problem but SMART shows some issues, so run an extended SMART test on that disk.

Assuming emulated disk is still mounting and contents look correct rebuild on top: https://wiki.unraid.net/Manual/Storage_Management#Rebuilding_a_drive_onto_itself

Not implemented yet, though since it uses a much newer kernel it's worth trying, the in tree driver might already work.

Oct 3 22:28:33 UNRAID kernel: BTRFS info (device md6): bdev /dev/md6 errs: wr 0, rd 0, flush 0, corrupt 149930, gen 0 Lots of corruption detected on that disk, and since it's the only one it might suggest a disk issue.

Hardware seems capable enough, though there might be a bottleneck if you have the HBA installed in the bottom slot, running a diskspeed test is a good idea to test disk speed and controller bandwidth.

Not necessarily, it dropped offline, this sometimes helps with that: Some NVMe devices have issues with power states on Linux, try this, on the main GUI page click on flash, scroll down to "Syslinux Configuration", make sure it's set to "menu view" (on the top right) and add this to your default boot option, after "append initrd=/bzroot" nvme_core.default_ps_max_latency_us=0 e.g.: append initrd=/bzroot nvme_core.default_ps_max_latency_us=0 Reboot and see if it makes a difference.

Disk appears to be in very bad shape, ddrescue recovery below high 90s percentile will make recovering that disk and the other one very difficult.

Rebooting should fix that.

Please post the diagnostics, mostly so we can the hardware.

IIRC both disks passed the extended SMART test, if yes they should be OK, so easiest way would be doing a new config (with the new disk15 also) and re-sync parity, then copy the data from the old disk15.

Do this first, you just need to backup the complete /config folder, everything important is inside that.

There's something reading from disk5.

This particular issue has been fixed since v6.10.0-rc5, you might have seen a different one, but we'd need the diagnostics to confirm.

Unraid driver is crashing, please reboot and try again, if you have the same problem post new diags.

Doesn't look like a disk problem, could be a power/connection issue, if the emulated disk is mounting and contents look correct you can rebuild on top, might be a good idea to replace/swap cables first to rule that out. You should also upgrade Unraid, you're using a very old release candidate.

Find it interesting that the board BIOS checks for that, you should be able to correct that with gdisk, e.g.: gdisk /dev/sdb GPT fdisk (gdisk) version 1.0.5 Caution: invalid main GPT header, but valid backup; regenerating main header from backup! Warning: Invalid CRC on main header data; loaded backup partition table. Warning! One or more CRCs don't match. You should repair the disk! Main header: ERROR Backup header: OK Main partition table: OK Backup partition table: OK Partition table scan: MBR: protective BSD: not present APM: not present GPT: damaged **************************************************************************** Caution: Found protective or hybrid MBR and corrupt GPT. Using GPT, but disk verification and recovery are STRONGLY recommended. **************************************************************************** Command (? for help): w Final checks complete. About to write GPT data. THIS WILL OVERWRITE EXISTING PARTITIONS!! Do you want to proceed? (Y/N): y OK; writing new GUID partition table (GPT) to /dev/sdb. The operation has completed successfully.

Looks OK for now.

It's a known issue, should be fixed for the next release.

Yes.

I assume the emulated disk mounted?

Looks like the NICs really have a problem, assuming you replaced/swapped cables before.

You'll restore the data to disk5 later from a backup or do you plan to try and recover the formatted data with UFS explorer or similar?

NIC link is going up very late, please post a set of diags without the Nvida driver for comparison.

Make sure all the standoffs are in their correct places.