Device is causing slow I/O on pool with CMR drives

[Archaniel]

Hello guys,

I've read through the other posts regarding this issue. I have a raidz2 with 6 drives, red/redpro and one green with flashed bios - all CMR.
It basically happens on all of the drives randomly, last july I had it simultaneously on 5 drives.
Not sure where to start from here or how to debug it what might cause the issue. smart doesnt report anything unusual.

also, why can't I post in Truenas general help forums? (says I dont have permission)

 

[Redcoat]

also, why can't I post in Truenas general help forums? (says I dont have permission)

General Help is in process of being closed out - look for recent post by @wsoteros which details it.

 

[Arwen]

Hmm, at least for the Green one, I would check TLER, Time Limited Error Recovery. Generally ZFS wants something reduced, like 7 seconds is common. Most desktop drives default to over a minute. When using RAID-Z2, it is usually better for ZFS to find the bad block and recover it from parity and re-write it. You get a minor warning and their would not be anything to do.

Oh, and the Green drive should probably also have the power management & acoustical settings at performance, not the low end.

But the Red & Red Pro drives should already have TLER set to a low amount.

Other drive vendors use different wording for TLER, but same concept.