RN314 HDD Failure, now running Degraded - Need some advice which HDD to purchase

[scrjs]

Hello Community

I have a RN314 that is running well and meeting my needs.

Overnight one of the HDD failed.  The logs shows the following messages

03 Jul 2024 07:37:56 AM	Volume: Volume data is Degraded.
03 Jul 2024 07:37:52 AM	System: ReadyNASOS service or process was restarted.
03 Jul 2024 05:10:37 AM	Volume: The resync operation finished on volume data. However, the volume is still degraded.
03 Jul 2024 05:10:17 AM	Volume: Volume data health changed from Redundant to Degraded.
03 Jul 2024 05:09:49 AM	Volume: Resyncing started for Volume data.
03 Jul 2024 12:01:06 AM	Volume: Disk test completed for volume data.
03 Jul 2024 12:01:06 AM	Volume: Disk test started for volume data.

I had installed 4 x WDC WD20EFRX-68EUZNN0 2TB HDDs with now one of them is offline.

These drives are, per https://kb.netgear.com/20641/ReadyNAS-Hard-Disk-Compatibility-List shown as

Give the age of the RN314 many of the drives are no longer available for purchase, including WD20EFRX.

I chatted with Western Digital online and the suggested I purchase a  WD2002FFSX which is on the compatibility list as follows

However I note (as highlighted) that the Disk RPM is 7200 vs 5400 for the remaining three HDDs.

• QUESTION 1: Can you mix HDDs in the RN314 with different Disk RPM specifications?
• QUESTION 2: Can you mix HDDs in the RN314 with different Cache specifications?

I understand that I can buy a larger capacity HDD, however the extra capacity will not be available till replace at minimum two HDDs with increased capacity (I am considering purchasing two 4TB HDDs) and I believe I need to do this in the sequence

1. Replace the failed drive.
2. Allow resync operation to finish. (no additional capacity will be available at this point even though one lager HDD is installed).
3. Remove a second, old WD20EFRX (one of the three remaining)
4. Allow resync operation to finish and system will be degraded
5. Replace with a second larger capacity HDD (same spec as installed in point 1)
6. Allow resync operation to finish after which the additional capacity should be available.

If I have this correct then I am considering purchasing TWO new HDDs (per spec below) so that I minimise the risk of further failures of the remaining WD20EFRX HDDs

• Question 3: Will this be successful given this HDD has a faster Disk RPM and larger Cache then the two old WD20EFRX HDDs?

Cheers Rob

( @StephenB & @B_L hope you both still out there and can help.  You have given me great advice in the past! 😁)

[Sandshark · Accepted solution]

Step one is to get that bad drive out of the system so it doesn't keep trying to re-sync the volume.  Even if it were to eventually succeed, you shouldn't trust that drive.  Those re-sync tries are putting stress on all your drives.

Step two is to make sure your backup is up to date.

Step three is to completely ignore the compatibility list.  It's woefully out of date.  @StephenB and I both recommend WD Red Plus or Red Pro or Seagate Ironwolf NAS-purposed drives.  Do not get a WD Red (non-plus, non-Pro), as they use SMR recording and WD is doing customers no favor when they say they are suitable for a NAS (they are certainly not suitable if that NAS uses RAID).  If you choose to look at other models, also insure that they use CMR, not SMR.  Many smaller drives do use SMR.

Yes, you'll need a second drive of a larger size to get a size increase.  But that's no reason not to get a larger drive as a single replacement if the space you have is currently enough.  Once you need more, you'll be able to just swap out a second one.  With today's prices, getting another 2TB just doesn't make sense, IMHO.

While the NAS will warn you about mixing drive speeds, it's not a real problem for desktop models.  The NAS won't care about cache size at all.  But be aware that a larger cache is often a sign it is an SMR drive.

Depending in part on the age of the existing drives, you may want to just start over with two much larger drives.  You've had one fail, so if the others are of the same age, they could fail soon as well.  Two 6TB drives will give you the same storage you currently have, though I'd probably go with at least 8TB.  When you add a drive, the NAS has to re-sync it, which puts a higher stress on the other drives.  A second drive failure during sync can kill your volume.  You'll need to back up and restore your data, of course, but hopefully you already have a backup plan.  And once you have a two-drive system, you just add another (same size or larger) to expand.

[Sandshark · Accepted solution]

Step one is to get that bad drive out of the system so it doesn't keep trying to re-sync the volume.  Even if it were to eventually succeed, you shouldn't trust that drive.  Those re-sync tries are putting stress on all your drives.

Step two is to make sure your backup is up to date.

Step three is to completely ignore the compatibility list.  It's woefully out of date.  @StephenB and I both recommend WD Red Plus or Red Pro or Seagate Ironwolf NAS-purposed drives.  Do not get a WD Red (non-plus, non-Pro), as they use SMR recording and WD is doing customers no favor when they say they are suitable for a NAS (they are certainly not suitable if that NAS uses RAID).  If you choose to look at other models, also insure that they use CMR, not SMR.  Many smaller drives do use SMR.

Yes, you'll need a second drive of a larger size to get a size increase.  But that's no reason not to get a larger drive as a single replacement if the space you have is currently enough.  Once you need more, you'll be able to just swap out a second one.  With today's prices, getting another 2TB just doesn't make sense, IMHO.

While the NAS will warn you about mixing drive speeds, it's not a real problem for desktop models.  The NAS won't care about cache size at all.  But be aware that a larger cache is often a sign it is an SMR drive.

Depending in part on the age of the existing drives, you may want to just start over with two much larger drives.  You've had one fail, so if the others are of the same age, they could fail soon as well.  Two 6TB drives will give you the same storage you currently have, though I'd probably go with at least 8TB.  When you add a drive, the NAS has to re-sync it, which puts a higher stress on the other drives.  A second drive failure during sync can kill your volume.  You'll need to back up and restore your data, of course, but hopefully you already have a backup plan.  And once you have a two-drive system, you just add another (same size or larger) to expand.

[StephenB]

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@scrjs wrote:

( @StephenB & @B_L hope you both still out there and can help.  You have given me great advice in the past! 😁)

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I agree with everything @Sandshark told you.

I'd add that you should download the full log zip, and take a look at disk_info.log.  That will give you some more details on overall disk health.

[scrjs]

Thank you BOTH @Sandshark & @StephenB !

Excellent as always 😁 Kudos to both!