(RN104) Length of Scrub Maintenance with 2x 4TB WD Red in Raid 1

[maik0055]

Hello,

I have a RN104 4-Bay Readynas with 2x 4TB WD Red Drives.
Scrubbing of those Drives takes (nearly) forever...

Its running since 8 hours and only reaced 1.1%
I was on firmware 6.9.5 with same problem.
Updated to 6.10 RC2 and problem persists.

Did a complete factory reset with only restoring data and starting with fresh config.
Same problem.

I had 4x1TB Drives bevore in Raid 5 and Scrubbing took about 24 hours.

I have enabled Bit-Rot-Protection.
Restoring the Data vom external USB3 Drive took about 28 hours for 2.65TB.

But is it normal, that scrubbing takes that long?!
I mean this would be about 25-30 days with constant scrubbing?!

I also have to say, that no one is using the nas so this could not be the case that it is sooo slow.

[StephenB]

It shouldn't be taking that long.  Have you downloaded the log zip file and looked at the disk health in disk_info.log?

Perhaps also try putting the disks in a Windows PC, and test them with lifeguard.

[maik0055]

I looked up disk health in webUI and shell with smartctl.
Both discs are good without any problem.

And I have to say that it is ok now. Scrubbing took 47 hours.
Before the factory reset I had it run for 2.5 days and was only at 9.75%.

Whatever the problem was, the factory reset and restoring only the data helped.