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Forum Discussion
chris2531
Sep 14, 2017Aspirant
RN102 fails to boot when one mirrored drive fails or is missing
Hello everyboby, I have been looking for a solution or help but was not able to find any hints regarding the following problem. I own a RN102 device equiped with two disk forming a X-RAID mirror...
- Sep 21, 2017
Well, it's still unclear to me what the root cause was. Somehow the RAID superblock that gets generated for the newly-added disk kept getting rejected because the kernel thought it was invalid. However, I don't know which part it thought was invalid, and there's no easy way to remotely debug at that low level.
Anyway, I got your box fixed up by restoring a good superblock made on another machine to your disk, and it's resyncing now and looks normal. I also made sure that volume repair worked after simulating a failure, so I don't think you'll run into this again. If you do, please let me know.
StephenB
Sep 14, 2017Guru - Experienced User
I think the first thing to do is make sure you have a current backup of the data.
At the moment does the volume tab show the RAID status as redundant or degraded?
If it is redundant, then download the log zip file. Look in disk_info.log at the SMART status for both disks. Maybe also look in mdstat.log, and see if the RAID array is using both disks.
If the disks are healthy and you have a backup, then you can do a factory reset (with the original disk 1 and the replacement disk 2). Then rebuild the NAS and restore the data. But Netgear might want to look at your logs before you do that, so I suggest holding off on the "nuclear" option for now.
- chris2531Sep 14, 2017Aspirant
Hello Stephen,
thank you for the answer. The disks seem ok, the system indicator is healthy but I cannot find any explicit indicator for the RAID Volume. Disk logs and mdstat.log indicate everything as ok (raid level 1, state clean for the two system set and the data set)
So, I guess I do not have to worry about loosing data shortly (and I got backups too).
But why is the device stopping to work when one disk is pulled and even not willing to boot? Doing a factory reset is honestly not a good solution. To protect from such disk failure szenarios I got the RAID1 setup. But this makes no sense when I have to do a factory reset every time a disk fails........
Greetings
Chris
- StephenBSep 14, 2017Guru - Experienced User
chris2531 wrote:
But this makes no sense when I have to do a factory reset every time a disk fails........
Of course you shouldn't have to do this, so something is definitely wrong.
An alternative to the factory reset is to remove the mis-behaving disk, and then unformat it in a PC. With windows you can do that by going into the windows disk manager and deleting each of the "Volumes" it shows on the disk (they are really partitions). You can also zero the disk with vendor diags (The quick zero test in WDC's lifeguard program will do the job nicely). Then hot-insert the drive, and the NAS should rebuild it. That includes rebuilding the OS partition on it, and any boot sector information.
Though I still recommend waiting for a bit to see if Netgear wants to take a look. Your problem is a bit unusual I think.
- mdgm-ntgrSep 15, 2017NETGEAR Employee Retired
Please send in your logs (see the Sending Logs link in my sig)
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