RN104 Remove inactive volumes to use the disk. Disk 1,2,3,4 after Firmware upgrade

Hi Jumanji2 

Thanks for sending the logs over. I took a look at them

Your data raid assembled fine, so it is not a "raid failure" causing this problem.

[Mon Mar 8 19:33:26 2021] md/raid:md127: raid level 5 active with 4 out of 4 devices, algorithm 2.
[Mon Mar 8 19:33:26 2021] md127: detected capacity change from 0 to 11987456360448.

However, the BTRFS filesystem is unable to mount mount due to a ctree failure. This is the reason you see that cryptic message in the ReadyNAS web admin page and the reason you cannot access you data. The below ctree error typically refers to the fact that the filesystem cannot use the superblocks which are needed in order to mount the filesystem. I don't see any signs of actual filesystem corruption but BTRFS cannot mount. This is generally painless to fix because BTRFS saves extra copies of the superblocks at different locations and thus you might be able to mount using a copy of a superblock, or even run btrfs rescue super-recover to try to fix it. Honestly, even a manual mount with recovery option might fix it.

[Mon Mar 8 19:33:27 2021] BTRFS info (device md127): setting nodatasum.
[Mon Mar 8 19:33:39 2021] BTRFS info (device md127): creating UUID tree.
[Mon Mar 8 19:33:39 2021] BTRFS warning (device md127): failed to create the UUID tree: -28.
[Mon Mar 8 19:33:40 2021] BTRFS error (device md127): open_ctree failed.

However, this still requires some knowledge of BTRFS and Linux and isn't something to attempt over a forum :)
Contacting Netgear for some paid support or pay some people that really know what they are doing, is your best course of action. StephenB might know if data recovery contracts are still a thing in Netgear.

Prior to this, you did an upgrade from really old code and thus the filesystem was created years ago when BTRFS was in its infancy. I wonder if this might have something to do with it... Not sure but I feel it does.

[2014/12/22 12:15:22] Defaulting to X-RAID2 mode, RAID level 5
[2014/12/22 12:15:51] Factory default initiated on ReadyNASOS 6.1.8.
[2021/03/08 01:30:52] Updated from ReadyNASOS 6.1.8 () to 6.2.5 (ReadyNASOS).
[2021/03/08 01:41:41] Updated from ReadyNASOS 6.2.5 (ReadyNASOS) to 6.5.2 (ReadyNASOS).
[2021/03/08 08:51:02 UTC] Updated from ReadyNASOS 6.5.2 (ReadyNASOS) to 6.10.4 (ReadyNASOS).

As a side note, disk 1 is failing in your NAS and you should replace it whenever your are out of this situation.

[21/03/05 11:24:33 GMT] notice:disk:LOGMSG_SMART_UNCORR_ERR_WARN Detected increasing uncorrectable error count: [32] on disk 1 (Internal) [ST4000DM000-1F2168, Z3013XS7]. This condition often indicates an impending failure. Please be prepared to replace this disk to maintain data redundancy.

[21/03/05 11:24:37 GMT] notice:disk:LOGMSG_SMART_ATA_ERR_30DAYS_WARN Detected increasing ATA error count: [773] on disk 1 (Internal) [ST4000DM000-1F2168, Z3013XS7] 39 times in the past 30 days. This condition often indicates an impending failure. Please be prepared to replace this disk to maintain data redundancy.

Long story short, I don't believe the filesystem is corrupt but rather that there is a problem with the superblocks. This should be recoverable but you need someone who knows what they are doing. And replace the bad disk once you have the data back.

Cheers