ReadyNAS 314 says "Volume data is degraded", but no errors in logs or disk reports

[jmegner]

I have a RN31400.  In the web interface, Admin page, System tab, it says "Status: Degraded".  It's been saying that for a while.

In the Volumes tab, it shows I have one RAID 5 volume with 3 disks and says "Volume is degraded".  When I mouse over each of my 3 disks in the Volumes tab, I don't see any problems with any disk (for example, no reallocated sectors, no uncorrectable sectors).

In the Logs tab, I see a bunch of "Volume: Volume data is degraded" messages and info about successful operations.  There are no warnings or errors other than about volume data being degraded.  There are some old antivirus-definition-out-of-date errors but they are very old and don't seem relevant.

I also downloaded the logs.  I didn't see anything in smart_history.log, systemd-journal.log, or disk_info.log that seemed relevant, other than a repeat of "volume data is degraded".

I've looked on the forum about the "volume data is degraded", but usually they have some visible problem with one of the disks, or that there's a new disk.  I don't have any new disks.  A while ago I did switch out an old RN31400 for a new RN31400 because it got fried during a power surge.

What next step should I take to diagnose/fix the problem?

[mdgm-ntgr · Accepted solution]

You only have 3 of your 4 disks installed. That's why it is showing degraded. If the disk you removed is faulty you'd need to add a new good disk. Until a replacement disk is added and the resync completes your volume will remain degraded and very vulnerable to any disk failing.

Is your backup up to date? If not, you may wish to update that as your next step.

[StephenB]

It'd be good to look in mdstat.log and volume.log (both are in the log zip).

Look for any indication that one of your disks is marked as "spare".  Also confirm that they both show 3 disks in the array, and not 4.

[jmegner]

>Look for any indication that one of your disks is marked as "spare". Also confirm that they both show 3 disks in the array, and not 4.

mdstat.log says that for /dev/md/0 and /dev/md/data-0, I have...

State : clean, degraded

Active Devices : 3

Working Devices : 3

Failed Devices : 0

Spare Devices : 0

For /dev/md/1, it was the same except the state was just clean.

volume.log repeatedly showed 3 devices (sda, sdb, sdc) and occasionally said some things were degraded.

Should I attach some logs?

[StephenB]

I suggest PMing mdgm with a link to this thread, and ask him if he can analyze your logs.

If he agrees, then email the logs as instructed here: https://kb.netgear.com/21543/How-do-I-send-all-logs-to-ReadyNAS-Community-moderators?cid=wmt_netgear...

[jmegner]

Thanks so much.  I have messaged mdgm.

[mdgm-ntgr]

Please send in your logs (see the Sending Logs link in my sig)

[jmegner]

I have emailed the zip of the logs according to the instructions in your signature.  Thanks!

[mdgm-ntgr · Accepted solution]

You only have 3 of your 4 disks installed. That's why it is showing degraded. If the disk you removed is faulty you'd need to add a new good disk. Until a replacement disk is added and the resync completes your volume will remain degraded and very vulnerable to any disk failing.

Is your backup up to date? If not, you may wish to update that as your next step.

[jmegner]

Thanks so much for your help.

>You only have 3 of your 4 disks installed.

Wow, I have no memory of a 4th disk, but my Newegg order history from years ago does show 4 disks, not 3.  What log helps show volume information like how many disks are expected, and so on?

[mdgm-ntgr]

Logs like mdstat.log for example.

[jmegner]

Ah, thanks.