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Aspirant

Jan 27, 2019

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volume degraded after disk swap on a RN312

Hi there,

I run a RN312 with two 6TB western digital red drives runing x-raid. one of them started having an increasing reallocated sector count, so I replaced it with another drive of the same type.

so far so good. after re-syncing had been completed the volume is now degraded. rebooting the RN triggers a new re-sync with the same result - a degraded volume. mdstat.log claims I have two working devices (drives), one active and one spare.

is there any way to recover from this outside of a factory reset (there is a backup, however on the other end of a very slow connection, so I'd rather not have to restore)...

thanks for any pointers...

best,

Lorenz

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lorenz
Feb 02, 2019
that's right, I did replace it with one of the same type and size...

I did a factory reset and the volume ist healthy again now, "just" need to restore the back up after updating the ssh setup with the newly generated keys....ah well....

thanks for thinking along sandshark & stephenB!

best,

Lorenz

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StephenB
Guru - Experienced User
Jan 27, 2019
You might try removing the spare and then confirming that you still have access to your data.

Then unformat the spare with Western Digital's lifeguard program in a Windows PC. The quick "write zeros" test will do that nicely.

After that hot-insert that drive into the NAS, and it should re-add it to the array (hopefully not as a spare this time).
- lorenz
  Aspirant
  Jan 29, 2019
  thanks a lot for the ideas stephen! I did as you suggested: data was still there after removing the new disk that was only recognized as spare. re-wrote it will all zeros. powered down the RN, reinserted the wiped disk, powered it up again, it synced: same result - volume is still degraded..:-(
  
  on the up side I now have a hard drive docking station to wipe and re-use my old drives..;-)...
  
  I just realized I did deviate from your suggestion in one point: I did not hot-insert the wiped drive as that did not work the 1st time. could that make a difference? if not: any other ideas?
  
  thanks & best,
  
  lorenz
  - StephenB
    Guru - Experienced User
    Jan 29, 2019
    lorenz wrote:
    
    I did not hot-insert the wiped drive as that did not work the 1st time. could that make a difference? if not: any other ideas?
    
    Hot-insertion is better because the NAS detects the insertion. If you insert with the NAS powered down, it needs to figure out that an insertion was done.
    
    The net here though is that the NAS is insisting on marking the drive as a spare. One thing you could try (painful) is to do a factory reset with both drives in place. After a successful RAID sync you'd have to restore the data from backup.
    
    You could also try paid support via my.netgear.com.