JorgeB

Or at least disable hard links : Settings > Global Shares Settings -> Tunable (support Hard Links): no

Wasn't it one array disk and one unassigned disk? But anyway, if accessing disk1 accessed a different unassigned (or assigned) disk they were almost certainly part of the same pool, but if it's fixed now it's not possible to confirm, we'd need to see before doing this: Because doing this wiped that device.

What HBA and enclosure?

External SAS, it also works with SATA devices.

Sounds like both disks were previously part of a btrfs pool, and if you did a new config the array disk wouldn't be cleared, you'd need to wipe one of the devices (or both) before use in the array.

Please start a new thread in the general support section, don't forget to include the diagnostics (after array start).

Try disabling NFS, if you can use SMB instead.

Just a reminder that you can't interrupt the procedure after the copy and before pressing start by rebooting or powering down, or you'll need to start over the procedure from the beginning.

Those speed graphs show the problem, maybe a SAS2LP issue with v6.9? Strange that I don't remember seeing anyone else complaining, and despite those controllers not being recommended I suspect there are still a few in use, could also be other hardware issue with the newer kernel, not controller related.

With most btrfs filesystem corruption issues best bet is to backup and re-format the device/pool, than restore the data.

Correct, and the steps look good.

Yep.

Post new diags after array start to see what's wrong with disk18.

You already have disk7 disabled, you can only have one disable/missing device with single parity, and first need to replace that one.

You might, but it's not that complicated, step by step instructions are easy to find.

Try that, but the problem might be the SATA port multiplier, it's not a recommended configuration, and known to cause issues with some devices.

https://forums.unraid.net/topic/46802-faq-for-unraid-v6/?do=findComment&comment=700582

That's a known issue, it's in the release notes for v6.9, you need to re-assign your cache/pool.

Replace cables, if issues persist post the complete diagnostics.

Yes, safely.

The Unraid driver is crashing, this happens with some hardware, don't no the reason or a solution, you can try v6.10-rc, it might not happen with the newer kernel.

Please use the existing plugin support thread:

Because according to Unraid one of them is not correctly assigned. File system is fully allocated, that's why it's running out of space, a balance would fix it but it won't work with the misassigned device, since the pool goes read only after the error. If array auto-start is enable disable it by editing /config/disk.cfg in the flash drive and changing startArray="yes" to "no", then reboot and post a screenshot of main before array start.

Good to know, but that wasn't an Asmedia 1166, those have only 6 ports and enough bandwidth for 6 HDDs, that was an Asmedia 1064 4 port controller likely with a SATA port multiplier on one of the ports.

Cache pool has too many missing devices: Oct 14 07:52:17 My-NAS emhttpd: shcmd (98): mkdir -p /mnt/cache Oct 14 07:52:17 My-NAS emhttpd: /mnt/cache uuid: 1eaddf7b-e831-47dc-89f0-98ed5e0d8894 Oct 14 07:52:17 My-NAS emhttpd: /mnt/cache TotDevices: 9 Oct 14 07:52:17 My-NAS emhttpd: /mnt/cache NumDevices: 6 Oct 14 07:52:17 My-NAS emhttpd: /mnt/cache NumFound: 6 Oct 14 07:52:17 My-NAS emhttpd: /mnt/cache NumMissing: 3 Oct 14 07:52:17 My-NAS emhttpd: /mnt/cache NumMisplaced: 0 Oct 14 07:52:17 My-NAS emhttpd: /mnt/cache NumExtra: 0 Oct 14 07:52:17 My-NAS emhttpd: /mnt/cache LuksState: 0 Oct 14 07:52:17 My-NAS emhttpd: /mnt/cache mount error: Too many missing/misplaced devices Plex pool has one misplaced device and is crashing on mount, post the output of: btrfs fi usage -T /mnt/plex