I have an old Synology DS209 running DSM 4.2-3256 and have 2 hard disks installed (raid 1) I have read something similar on How can I verify the health of hard disks using a Synology NAS?

And have searched the Synology knowledge base, but could not find a thing.

We have two Western Digital WD10EADS-00M2B0 and I got a message about the 2nd disk smart error. Disk 2 is also 4 degrees Celsius warmer than the 1st disk. When I run a fast or extended smart check on the second disk, it stops at 90%. The first disk completes fine.

I have compared the stats for disc 1 with 2 and am wondering if there really is a problem? I think the multi_zone_error_rate shows there is, doesn't it? according to https://forum.synology.com/enu/viewtopic.php?t=81364 it shows that the mechanical state of our disk is bad. Which is confirmed at WikiPedia.

So why does Synology keeps showing status OK when smart does not complete?

Can someone confirm that I have to replace the disk?

disk 1: (normal) enter image description here

disk 2: (smart stops at 90%) enter image description here

1 Answer 1


This sounds pretty unfortunate, @JP Hellemons! :( The Multi-Zone Error Rate/Write Error Rate is a critical parameter. It indicates the total number of errors appearing while recording data to a hard drive. If it has started degrading, it might indicate electromechanical problems of the disk. This means that it could be caused by problems with the disk surface of the HDD heads, which might be considered a hardware corruption. I'd advise you backup your data from the RAID 1 somewhere else and consider replacing the failed WD drive. If the drives came with your NAS enclosure, contact the NAS manufacturer's customer support for assistance. If it's still covered by the warranty, you should be able to RMA the failed HDD and get a replacement from them.

Your RAID 1 should be able to work with only one HDD in the NAS, but I'd still make a copy of the data somewhere else as well. Having multiple copies is the best way to avoid any potential data loss.

Another thing you could try is running the QUICK and EXTENDED tests from the WD Data LifeGuard Diagnostics for DOS. (You should be able to see the DOS Version, once you select a WD internal HDD) I'd also advise you to follow the instructions on how to run the tests from this utility. If any errors occur again, you should definitely consider replacing the drive ASAP.

Hope this helps you. Best of luck!

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.