Volume Degraded, Raid1 Problem?

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mattius
Posts: 18
Joined: Wed Oct 08, 2014 4:07 pm

Volume Degraded, Raid1 Problem?

Post by mattius » Sun Sep 11, 2016 6:07 pm

Hello, I have an NSA325 v2 NSA with 2 x Western Digital 2tb drives in a Raid1 Configuration. This morning I noticed that the disc Space left was very low, (9gb). So I deleted a large file to free up some space. However I noticed Internal Volume Status had become degraded despite having freed up an extra 160gb. I scanned the volume & it reported no problems. At one point the Disc 1 drive light on the front of the NAS had turned red. I rebooted unit & the red light has now turned green but the Internal Status is still showing degraded. I did a hard reset system. Sadly the Internal volume status is still degraded. The status screen it now only shows Disc2 & Not Disc1 & Disc2! However on the smart status it still shows both.
I guess one of the drives, drive 1? Is failing. I have a new drive but not sure which to replace as they are not labeled? Should I replace one of them? Help would be greatly appreciated. Thanks in advance :?

Mijzelf
Posts: 6224
Joined: Mon Jun 16, 2008 10:45 am

Re: Volume Degraded, Raid1 Problem?

Post by Mijzelf » Mon Sep 12, 2016 8:54 am

mattius wrote:However I noticed Internal Volume Status had become degraded despite having freed up an extra 160gb.
That is unrelated. Degraded means that one disk of your 2 mirrored disks is dropped from the array. It has nothing to do with the filesystem on that array.
I scanned the volume & it reported no problems.
Again, unrelated. The filesystem is fine, but the volume has no mirror anymore.
The status screen it now only shows Disc2 & Not Disc1 & Disc2! However on the smart status it still shows both.
I guess the smart status of disk1 is bad?

I guess one of the drives, drive 1? Is failing. I have a new drive but not sure which to replace as they are not labeled? Should I replace one of them?[/quote]Yes, you have to replace the faulty disk. The replacement disk needs to be at least as big.
I'd expect disk 1 to be the left one. You can simply pull it (after powering down), and see if the volume is still accessible. If not, power down, and try the other.

mattius
Posts: 18
Joined: Wed Oct 08, 2014 4:07 pm

Re: Volume Degraded, Raid1 Problem?

Post by mattius » Mon Sep 12, 2016 9:43 am

Thanks for coming back. I did not se any problem when looking at the Smart status of either drive. Surely if the drive is sick it would show? I attach some screenshots.....
Capture1.JPG
Capture2.JPG
Disc 1 (a)
disc1a.JPG
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Last edited by mattius on Mon Sep 12, 2016 9:45 am, edited 1 time in total.

mattius
Posts: 18
Joined: Wed Oct 08, 2014 4:07 pm

Re: Volume Degraded, Raid1 Problem?

Post by mattius » Mon Sep 12, 2016 9:44 am

Disc 1 (b)
disc1b.JPG
Disc 2 (a)
disc2a.JPG
Disc 2 (b)
disc2b.JPG
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Mijzelf
Posts: 6224
Joined: Mon Jun 16, 2008 10:45 am

Re: Volume Degraded, Raid1 Problem?

Post by Mijzelf » Mon Sep 12, 2016 11:39 am

Indeed smart doesn't say anything alarming. Disk2 has a far higher load cycle count than Disk1 has. As Disk2 is a WD green, and Disk1 is a WD Red, that's not strange. But maybe you'd better use wdidle3 to change the Green's setting.

But that has nothing to do with your current problem. Disk1 is dropped from the array, and so it doesn't show up in the volume list. But the disk is still physically present, and so it shows up in the SMART list. That makes sense.

Seeing this smart values I'd be tempted to just reinsert disk1 in the array, as it seems to be perfectly healthy. The webinterface doesn't seem to have a button for that. If you are not afraid for the command line, you could do it manually. Something like

Code: Select all

mdadm --add /dev/md0 /dev/sda2
But you'll have to check if it's really /dev/sda2 which is dropped, maybe by looking at the current status

Code: Select all

cat /proc/mdstat

mattius
Posts: 18
Joined: Wed Oct 08, 2014 4:07 pm

Re: Volume Degraded, Raid1 Problem?

Post by mattius » Mon Sep 12, 2016 4:19 pm

Think you've gone a bit over my head. No idea what a wdiddle3 is? Also not sure where or how to do CLI to reinsert disk1 in the array???? :oops:

Mijzelf
Posts: 6224
Joined: Mon Jun 16, 2008 10:45 am

Re: Volume Degraded, Raid1 Problem?

Post by Mijzelf » Mon Sep 12, 2016 7:24 pm

wdidle3.

About the command line, there are several options. you can use the Telnet backdoor, or install MetaRepository, and use that to install Dropbear, an ssh server. Or use MetaRepository to install Tweaks, to enable the build-in Telnet daemon.

Or install AnyTerm, to get a terminal in your browser.

mattius
Posts: 18
Joined: Wed Oct 08, 2014 4:07 pm

Re: Volume Degraded, Raid1 Problem?

Post by mattius » Tue Sep 13, 2016 10:18 am

Sorry & thanks but you have me stumped :?

mattius
Posts: 18
Joined: Wed Oct 08, 2014 4:07 pm

Re: Volume Degraded, Raid1 Problem?

Post by mattius » Wed Sep 14, 2016 4:50 pm

I removed Disc1, (WD RED), & replaced it with a new one. I then repaired Raid & now it is healthy!! :D

It seems to have worked. I'll check the drive connected to my PC to see if diagnostic programs can shed any light? It must have been the drive although SMART showed no problem. Any comments from you are welcome. :?:

mattius
Posts: 18
Joined: Wed Oct 08, 2014 4:07 pm

Re: Volume Degraded, Raid1 Problem?

Post by mattius » Wed Sep 14, 2016 8:13 pm

Update, I appear to have lost a couple of directories adding up to about 400gb? The size of the Raid is as it was, 1.79gb but the file system now only uses 1.4. What's happened to the extra 400gb that the directories I lost should have freed up?? :?

Mijzelf
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Joined: Mon Jun 16, 2008 10:45 am

Re: Volume Degraded, Raid1 Problem?

Post by Mijzelf » Thu Sep 15, 2016 5:35 am

mattius wrote:Any comments from you are welcome. :?:
The only comment I have is that, despite it's reputation, a WD Red is not especially suitable for a consumer NAS. In contrary. It has TLER (Time limited Error Recovery) meaning it will not spend much time on reading hard-to-read sectors. Instead it will fail. This firmware addition is needed for some hardware RAID controllers, but not for Linux software RAID, which is running on each consumer NAS I know of. So the net result is that a Red is more likely to be dropped from an array than a hardware identical Green. (Although a Green can have firmware additions which make it wear down faster)
mattius wrote:Update, I appear to have lost a couple of directories adding up to about 400gb? The size of the Raid is as it was, 1.79gb but the file system now only uses 1.4. What's happened to the extra 400gb that the directories I lost should have freed up?? :?
That is strange, and should be unrelated to RAID problems, as the RAID system doesn't touch the file system.
Did you identify the lost files? Is it possible that the firmware flushed some cache, maybe triggered by the RAID resync?

mattius
Posts: 18
Joined: Wed Oct 08, 2014 4:07 pm

Re: Volume Degraded, Raid1 Problem?

Post by mattius » Thu Sep 15, 2016 8:29 am

Thanks, the weird thing is that the used disc space is equal to what it was before I lost my "Backup" directory which contained approx 400gb of image files. It's as if the "Missing" files are still there taking up the space but I cannot see/access them! WEIRD!

Mijzelf
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Joined: Mon Jun 16, 2008 10:45 am

Re: Volume Degraded, Raid1 Problem?

Post by Mijzelf » Fri Sep 16, 2016 10:32 am

Have a look at the shares menu. Maybe you just have to re-enable some share.

mattius
Posts: 18
Joined: Wed Oct 08, 2014 4:07 pm

Re: Volume Degraded, Raid1 Problem?

Post by mattius » Fri Sep 16, 2016 5:49 pm

The whole system had now died. My RAID is down! Bought new NAS today. Will check drives soon using UFS Explorer. Just trying to decide whether I need UFS Explorer Standard Recovery @ 39.95 euro or the UFS Explorer Standard Access @ 21.95 Euro! :?:

Mijzelf
Posts: 6224
Joined: Mon Jun 16, 2008 10:45 am

Re: Volume Degraded, Raid1 Problem?

Post by Mijzelf » Sun Sep 18, 2016 1:11 pm

As far as I know you can simply try it without purchasing anything. The freeware version is limited, it won't let you copy the files away, but if it can see the files that version is sufficient.

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