On 11/06/2014 12:12 PM, Vince wrote:

Hi Phil,

quoted

This is a problem you haven't solved yet, I think.  The raid array
should have fixed this bad sector for you without kicking the drive out.
The scenario is common with "green" drives and/or consumer-grade
drives in general.

i investigated some time and now i am a bit confused.

All my 5 WD Red drives have ERC enables (7sec)
The kernel timeout is set to 30sec (/sys/block/sdb/device/timeout)
on all devices.

Unfortunately i haven't any backup of the dmesg output, but i can remeber i
got something like:
"failed command: READ FPDMA QUEUED status: { DRDY ERR } error: { UNC }".
This shows up several times until it ends with showing me the sector which
causes the problem.

My raid is still up, but as you mentioned i would like some kind of self
repair if a sector is unreadable instead throwing the disk out of the array.

Here is the samrtctl of one drive that fails.

Do you have any idea if i missing some settings etc?

Interesting.  I use the WD Red drives, too, and recommend them.  Your 
drive's smartctl report is clean as far as wear & tear is concerned. 
That suggests a hardware problem elsewhere in your system.  Bad cable, 
perhaps, or a failing power supply.

Beyond that, I can only recommend regular "check" scrubs, with "repair" 
scrubs only when mismatches are discovered.

Phil