netgear redynas rn2120v2 - inactive volume

Hi alaaes 

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

The data volume appears dead because it cannot mount. Your disks and raids are fine but the volume filesystem is damaged. This likely happened because the volume got very full.

[19/04/09 01:24:25 EET] warning:volume:LOGMSG_VOLUME_USAGE_CRITICAL Less than 5% of volume MayData's capacity is free. MayData's performance is degraded and you risk running out of usable space. To improve performance and stability, you must add capacity or make free space.

Shortly after the data volume getting so full, we see it go into read-only mode due to filesystem errors.

[19/04/12 23:05:20 EET] warning:volume:LOGMSG_VOLUME_READONLY The volume MayData encountered an error and was made read-only. It is recommended to backup your data.

Upon next boot, the volume can no longer mount. Here are the filesystem errors upon the boot.

[Sat Apr 13 00:06:29 2019] BTRFS: device label xxxxxxxx:MayData devid 1 transid 267526 /dev/md127
[Sat Apr 13 00:06:30 2019] BTRFS info (device md127): setting nodatasum
[Sat Apr 13 00:06:30 2019] BTRFS info (device md127): has skinny extents
[Sat Apr 13 00:06:30 2019] BTRFS error (device md127): bad tree block start 2243902102695562974 18224709369856
[Sat Apr 13 00:06:30 2019] BTRFS error (device md127): bad tree block start 2243902102695562974 18224709369856
[Sat Apr 13 00:06:30 2019] BTRFS warning (device md127): failed to read tree root
[Sat Apr 13 00:06:30 2019] BTRFS error (device md127): bad tree block start 2243902102695562974 18224709369856
[Sat Apr 13 00:06:30 2019] BTRFS error (device md127): bad tree block start 2243902102695562974 18224709369856
[Sat Apr 13 00:06:30 2019] BTRFS warning (device md127): failed to read tree root
[Sat Apr 13 00:06:30 2019] BTRFS error (device md127): bad tree block start 11380574474146357643 18224706617344
[Sat Apr 13 00:06:30 2019] BTRFS error (device md127): bad tree block start 11380574474146357643 18224706617344
[Sat Apr 13 00:06:30 2019] BTRFS warning (device md127): failed to read tree root
[Sat Apr 13 00:06:30 2019] BTRFS error (device md127): bad tree block start 18374686479654780670 18224704028672
[Sat Apr 13 00:06:30 2019] BTRFS error (device md127): bad tree block start 18374686479654780670 18224704028672
[Sat Apr 13 00:06:30 2019] BTRFS warning (device md127): failed to read tree root
[Sat Apr 13 00:06:30 2019] BTRFS error (device md127): bad tree block start 13915544454450785711 18224701997056
[Sat Apr 13 00:06:30 2019] BTRFS error (device md127): bad tree block start 13915544454450785711 18224701997056
[Sat Apr 13 00:06:30 2019] BTRFS warning (device md127): failed to read tree root
[Sat Apr 13 00:06:30 2019] BTRFS error (device md127): open_ctree failed

BTRFS, as with other filesystems, struggle when you fill it so much. I suspect that it encountered some corruption due to lack of free space.

In any case, you need assistance getting the data volume back. The above filesystems errors are usually recoverable and data can typically be restored. There are several BTRFS built-in tools to deal with this.

If the data is important and you don't have a backup, then I recommend that you contact NETGEAR and enquire about a data recovery contract. They can help attempt to restore the data (best effort basis) but it will cost a couple hundred bucks minimum.

Cheers