Readynas RNDU6000 says "Volume data is degraded", no errors in disk status

[Khobayachi]

Hi,

I have a Readynas Ultra 6 (RNDU6000). On the NAS screen and on the admin page, it says "DEGRADED" for a few weeks.

The Volumes tab shows one volume, Data, with 6 disks. WHen I roll over each disk with my mouse, I don't see any errors (No ATA erros and they are all online).

I've nearly finished a backup of the volume. What should I do next ?

Thanks for your help

[StephenB · Accepted solution]

As far as disk health goes - you might want to repeat those tests, but this time run the destructive "write zeros" test.  I've found that will pick up issues that the non destructive tests miss.

The easiest way to test the SATA backplane is to do a factory reset with only one disk installed in slot 1.  When that completes, make sure you can read/write to the data volume, and of course look at the log for any problems. Then power down the NAS, and move that disk to slot 2.  Power up, and make sure the system boots and still functions normally.  Repeat that until you have tested all 6 slots.

Another possibility is that you have a failing power supply - not always able to provide adequate power to all the disks.  A memory failure can of course also create all kinds of weird symptoms, but I won't expect it to only affect the mounting of the RAID array.

[Marc_V]

Hi @Khobayachi

Welcome to the Community!

Have you tried downloading the logs? You can check on smart_history or diskinfo and mdstat to see if the disks and array are fine if it's not showing on the admin page just to make sure. You can PM me a link to download it and check it for you.

It's good you have done full backup, a Factory reset might be best but we have to make sure there's nothing wrong with the disks and/or the chassis.

Hope this helps!

Regards

[Khobayachi]

Hi Marc,

Unfortunatelly, things have changed since my first post.

I noticed drives 4 and 5 had a 0 RPM, altough they were showing no errors. I decided to eject both of them, and insert them again. As soon as I did the whole volume passed from DEGRADED to DEAD 😕

I'm sending the logs (before and after the crash) following your procedure.

Thanks for your help.

[Khobayachi]

Hi Marc,

I 've sent the logs.

After rebooting the Nas, the status is now "Clean" (the same in mdstat.log), but the Volume tab shows 3 volumes (see screenshot). None of these volumes can be see in the "Shares" menu.

Disks 4 and 5 still shows a 0 RPM. Are they dead ? Any chance I can get my previous volume Data back (my backup wasn't quite over) ?

Thanks

[Sandshark]

Unless you were  at RAID6, ejecting 2 drives at the same time killed your volume, at least assuming you did it with power on (which is how I interpret your post) .  I suspect that only one of them was actually the problem.  Since the drive is what reports SMART errors, a completely dead one can't report any.  And I think the NAS does not try to read them from a spun-down drive, either.  But if two drives were dead, your volume should have been dead, not degraded, and some files would not back up.  Of course, if only one were dead and you ejected the wrong one, the same thing would have happened.

The three volumes you see are not valid.  It's just seeing a partition on each and thinking they are.  Given you did update your backup, the next steps are to determine which drive(s) really is/are dead, replacing any that need it, facory default, and restore data.  Just pat yourself on the back that you performed the right first step:  "Update backup."

[Khobayachi]

Hi Sandshark,

As suggested by Marc, I've reset the Nas to factory settings. Everything seemed to be fine just after factory settings. But this morning, after a night of resync, I noticed :

- drives 2 and 3 are said to be inactives (altough when I roll over them with my mouse, their status is "ONLINE")

- a second volume "data -1" appeared after sync

- Drive 4 and 5 still show a 0 RPM when I roll over them with my mouse

Could it be an hardware issue (Sata controller dying) ? If yes, how can I diagnose it ?

Thanks for your help

[StephenB]

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@Khobayachi wrote:

Could it be an hardware issue (Sata controller dying) ? If yes, how can I diagnose it ?

---

More likely it's the disks.  The next step is to test the drives in a Windows PC with vendor tools (seatools for seagate, lifeguard for western digital).   You can connect the disks to the PC either with SATA or via a USB adapter/dock.

[Khobayachi]

Hi Stephen,

I have tested each drives on a PC with an usb/sata external case. Their smart status is good.

I also performed 2 reset to factory settings, after testing all the drives. Each time, once the resync was over (6 hours), I got 2 volumes, « Data » and « Data-1 » :

- volume « Data » : with drives 1,4,5,6

- volume « Data-1 » : with drives 2 & 3

Each time (Before and after resync) drives status is good and online, but drives 4 and 5 have a 0 RPM (see screenshot). This is really strange. What should I do ?

Thanks again.

 

[StephenB · Accepted solution]

As far as disk health goes - you might want to repeat those tests, but this time run the destructive "write zeros" test.  I've found that will pick up issues that the non destructive tests miss.

The easiest way to test the SATA backplane is to do a factory reset with only one disk installed in slot 1.  When that completes, make sure you can read/write to the data volume, and of course look at the log for any problems. Then power down the NAS, and move that disk to slot 2.  Power up, and make sure the system boots and still functions normally.  Repeat that until you have tested all 6 slots.

Another possibility is that you have a failing power supply - not always able to provide adequate power to all the disks.  A memory failure can of course also create all kinds of weird symptoms, but I won't expect it to only affect the mounting of the RAID array.

[Khobayachi]

Hi Stephen,

So far it seems you were right. I've tested and erased all 6 drives one by one (no smart errors). Then I took one of the WD30EFRX with the 80.00A80 firmware (I have two of them, they still show 0 RPM in the admin Volume tab, but it seems to be a firmware issue).

Then I have tested all the nas slots with one of them : factory reset and read/write test OK. I have made a last factory reset with all drives in the nas. It's still resyncing (9 hours left), but at least I didn't get a ghost Data Volume when installing them in the NAS.

I should know in a few hours if it worked, I'll keep you updated.

Thanks

[Khobayachi]

Hi Stephen,

Resync is completed and the Nas works fine now, I am currently restoring my data.

Thanks again