When you see this error message, chances are that you have an issue with either your raid or the filesystem on the raid volume. I can take a look at it for you, but I would need some logs.
You can download logs into a zip file. - Go to the ReadyNAS web admin page and navigate to "System" > "Logs". - Here you will see an option to "Download Logs" on the right-hand side. - This will download a zip file containing the logs.
Once downloaded, then upload to Google drive, Dropbox or similar and give me a link to download them. PM me this link, don't share it publicly here on the forums.
Thanks for sharing the logs with me. I had a look at them.
The good news is that your disks and raids are healthy. md127, which is your data raid, assembles and runs just fine. I checked your 3 disks and they are good too.
Personalities : [raid0] [raid1] [raid10] [raid6] [raid5] [raid4]
md127 : active raid5 sdb3[0] sda3[2] sdc3[1]
19523174272 blocks super 1.2 level 5, 64k chunk, algorithm 2 [3/3] [UUU] <<== all 3 disks are active in your data raid
md1 : active raid1 sdb2[0] sda2[2] sdc2[1]
523712 blocks super 1.2 [3/3] [UUU]
md0 : active raid1 sdb1[0] sda1[2] sdc1[1]
4190208 blocks super 1.2 [3/3] [UUU]
However, when the NAS attempted to mount the filesystem after the raid assemble, it failed. I appears that there is some corruption on the filesystem.
Raid is assembled and filesystem superblocks are read.
[Sat Dec 19 11:53:58 2020] md/raid:md127: raid level 5 active with 3 out of 3 devices, algorithm 2
[Sat Dec 19 11:53:59 2020] BTRFS: device label 062260fa:data devid 1 transid 178407 /dev/md127
[Sat Dec 19 11:53:59 2020] BTRFS info (device md127): setting nodatasum
[Sat Dec 19 11:53:59 2020] BTRFS info (device md127): has skinny extents
But the mount fails due to corruption on the filesystem.
[Sat Dec 19 11:53:59 2020] BTRFS error (device md127): bad tree block start 11265750982282334900 20127865176064
[Sat Dec 19 11:53:59 2020] BTRFS error (device md127): bad tree block start 11265750982282334900 20127865176064
[Sat Dec 19 11:53:59 2020] BTRFS warning (device md127): failed to read tree root
[Sat Dec 19 11:53:59 2020] BTRFS error (device md127): bad tree block start 11265750982282334900 20127865176064
[Sat Dec 19 11:53:59 2020] BTRFS error (device md127): bad tree block start 11265750982282334900 20127865176064
[Sat Dec 19 11:53:59 2020] BTRFS warning (device md127): failed to read tree root
[Sat Dec 19 11:53:59 2020] BTRFS error (device md127): bad tree block start 8171438277136941299 20127864225792
[Sat Dec 19 11:53:59 2020] BTRFS error (device md127): bad tree block start 8171438277136941299 20127864225792
[Sat Dec 19 11:53:59 2020] BTRFS warning (device md127): failed to read tree root
[Sat Dec 19 11:53:59 2020] BTRFS error (device md127): bad tree block start 17970008027056921816 20127859507200
[Sat Dec 19 11:53:59 2020] BTRFS error (device md127): bad tree block start 17970008027056921816 20127859507200
[Sat Dec 19 11:53:59 2020] BTRFS warning (device md127): failed to read tree root
[Sat Dec 19 11:53:59 2020] BTRFS error (device md127): bad tree block start 7422181120534201594 20127857410048
[Sat Dec 19 11:53:59 2020] BTRFS error (device md127): bad tree block start 7422181120534201594 20127857410048
[Sat Dec 19 11:53:59 2020] BTRFS warning (device md127): failed to read tree root
[Sat Dec 19 11:53:59 2020] BTRFS error (device md127): open_ctree failed
These issues are usually fixable. BTRFS as a filesystem has some good tools to recover from a scenario like this, such as mounting with recovery option or using BTRFS restore or even BTRFS repair to get the filesystem back to healthy terms. However, it requires that you know what you are doing, is very comfortable with Linux and BTRFS.
I would not recommend to dive into those waters without previous experience and would instead suggest to open a ticket with Netgear (you can refer to the analysis in this forum post here). They do offer (at least used to) data recovery contract where they can attempt to recover the data. If the corruption is really heavy (which isn't necessarily the case here) then they might not be able to fix it (it is a paid best effort thing) and would advise you to contact 3rd party data recovery experts instead (this can be expensive).
If the data does not matter to you or if you have a backup of the data, you can always factory reset the NAS (which will destroy the data volume and make a new volume and filesystem). Afterwards you can then restore from your backups.
First hint of the issue was on the 18th when the NAS remounted the volume as read-only as it detected filesystem issues.
[20/12/18 15:51:50 IST] warning:volume:LOGMSG_VOLUME_READONLY The volume data encountered an error and was made read-only. It is recommended to backup your data.
A reboot then occurred and now you are in this situation. I don't think you did anything wrong here per se. Filesystems can corruption for a wide array of reasons. I will say though, that in my opinion and experience, the ReadyNAS ARM units (such as yours) tend to see more corruption cases than the Intel units. This is especially true on large volumes (+10 TB) as you have. I suspect the ARM CPU just isn't properly capable of handling large volumes. This isn't a documented or advertised limit and I am sure many ARM units run large volumes out there in the world - it is just my experience and you can take that for what you want.
I am sorry I didn't have better news for you. If the data matters, contact Netgear to discuss data recovery contract. If it does not matter or if you have backups, then factory reset and start over (unless you want to dabble with trying to recover the volume by yourself).
I tried to reply to this post a few times. I got logs and had a look at them. But my reply isn't going through for some reason. It says it was successful but it never appears in the thread. Anything you can see on your end as to why that might be? Cheers
Re: Netgear RN214 error remove inactive volumes to use disk #1,2,3
Maybe my reply was too long? In any case, the issue is filesystem corruption on the data volume. Raids and disks are fine but it fails to mount the volume.
[Sat Dec 19 11:53:59 2020] BTRFS error (device md127): bad tree block start 11265750982282334900 20127865176064
[Sat Dec 19 11:53:59 2020] BTRFS error (device md127): bad tree block start 11265750982282334900 20127865176064
[Sat Dec 19 11:53:59 2020] BTRFS warning (device md127): failed to read tree root
[Sat Dec 19 11:53:59 2020] BTRFS error (device md127): bad tree block start 11265750982282334900 20127865176064
[Sat Dec 19 11:53:59 2020] BTRFS error (device md127): bad tree block start 11265750982282334900 20127865176064
[Sat Dec 19 11:53:59 2020] BTRFS warning (device md127): failed to read tree root
[Sat Dec 19 11:53:59 2020] BTRFS error (device md127): bad tree block start 8171438277136941299 20127864225792
[Sat Dec 19 11:53:59 2020] BTRFS error (device md127): bad tree block start 8171438277136941299 20127864225792
[Sat Dec 19 11:53:59 2020] BTRFS warning (device md127): failed to read tree root
[Sat Dec 19 11:53:59 2020] BTRFS error (device md127): bad tree block start 17970008027056921816 20127859507200
[Sat Dec 19 11:53:59 2020] BTRFS error (device md127): bad tree block start 17970008027056921816 20127859507200
[Sat Dec 19 11:53:59 2020] BTRFS warning (device md127): failed to read tree root
[Sat Dec 19 11:53:59 2020] BTRFS error (device md127): bad tree block start 7422181120534201594 20127857410048
[Sat Dec 19 11:53:59 2020] BTRFS error (device md127): bad tree block start 7422181120534201594 20127857410048
[Sat Dec 19 11:53:59 2020] BTRFS warning (device md127): failed to read tree root
[Sat Dec 19 11:53:59 2020] BTRFS error (device md127): open_ctree failed
I gave @manoj_328 are more thorough reply in PM. He/she should contact Netgear support regarding this (if no backup of data exists), as they can attempt to recover the volume.
I tried to reply to this post a few times. I got logs and had a look at them. But my reply isn't going through for some reason. It says it was successful but it never appears in the thread.
There's an automated spam filter that triggered for some reason. My understanding is that the mods are supposed to periodically go through the spam and manually release false triggers, but they often get behind. As you might imagine, there can be a lot of spam sometimes.
Anyway, I can release spam, and I just did that for your most recent message. If you see this again, you can PM me (and/or the mods).
