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RN104 fw:6.9.0 fail startup after RAID expansion
Had 3x 4TB drives and was getting close to hitting capacity. Added a 4th 4TB drive and waited a couple days for resync. At some point I saw RETRY STARTUP, and cannot power off without pulling plug....
Whompin105 wrote:
Any ideas about what might cause the non-fresh disk being kicked from the array?
Non-fresh means it's not in sync (meaning some writes never made it to the disk). So the real question is why it's not in sync. Was the NAS forcibly shut down before this (or suffer a power failure).
It is possible to force the array to assemble anyway. Though being out-of-sync could result in some file system corruption/loss.
Digging through all the log files to find anything resebling warnings or errors - it takes some time since I don't know where to look, but grep helped me find a few things. In kernal.log I see what looks like an attempt to create the raid 5 array, where it binds 4 devices but then has a line that says
"nas kernel: md: kicking non-fresh sda3 from array!"
I'm not sure exactly what this means, but I assume there's some issue with one of the disks, so it unbinds that one and then continues with the remaining 3 disks.
"nas kernel: md/raid:md127: raid level 5 active with 3 out of 4 devices, algorithm 2"
"nas kernel: md127: detected capacity change from 0 to 7991637573632"
"nas kernel: md: reshape of RAID array md127"
Then durring the reshape it appears there is an ATA error, not correctable errors on several sectors of sdd3 followed by:
"nas kernel: md/raid:md127: Disk failure on sdd3, disabling device."
So it appears that 1 of 4 disks is initally ignored due to it's "non-fresh" status, and then reshaping fails due to errors on one of the remaining 3 disks, so the RAID array never gets built and btrfs can't mount and I can't acess my data volume. Any ideas about what might cause the non-fresh disk being kicked from the array?
Whompin105 wrote:
Any ideas about what might cause the non-fresh disk being kicked from the array?
Non-fresh means it's not in sync (meaning some writes never made it to the disk). So the real question is why it's not in sync. Was the NAS forcibly shut down before this (or suffer a power failure).
It is possible to force the array to assemble anyway. Though being out-of-sync could result in some file system corruption/loss.
Ok, so here is my best guess as to what happened. The 4th disk was added for horizontal expansion, but before expansion completed power flickered out, so 4th drive is out of sync (shows 29k events as opposed to 35k on other disks). When power restored disk 1 had ATA errors preventing boot. After removing disk 1 and booting and upgrading FW, the NAS could boot with all 4 disks installed, but fails to asemple the array due to out-of sync disk4 and errors on disk1.
From ssh session I was able to mdadm force assemble the data array using disks 1-3, and leaving off the 4th out of sync disk. I'm not sure if data is all in tact due to possible bad disk 1, but I have the volume mounted now and am trying to back up what I can to USB external. I'm only getting ~25MBps so it's going to take 3 days to back up. This feels slow to me (like half what I would expect). I'm using a 8TB WD elements NTFS external and data consists mostly of large media files. I used the web interface backup funtion to initiate the transfer.
After the backup is complete, the question is what to do next. The array is degraded with disk 4 not included, but also possibly damaged due to disk 1 errors. Do I chuck disk 1, buy another disk, reset to factory and restore my backup? Or can I do something to get disk 4 in-sync and then replace disk1 with a new disk, potentially never losing access to the data in the process?
Whompin105 wrote:
After the backup is complete, the question is what to do next. The array is degraded with disk 4 not included, but also possibly damaged due to disk 1 errors. Do I chuck disk 1, buy another disk, reset to factory and restore my backup? Or can I do something to get disk 4 in-sync and then replace disk1 with a new disk, potentially never losing access to the data in the process?
Both are reasonable. If there is evidence of file system corruption as you do the backup, then the factory reset is the way to go.
If not, then you can always do the factory reset later on if you find evidence of corruption (as long as you keep the backup up to date).
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