I'm having some weird issues with my BTRFS raid 1 array lately (2x250gb samsung evo 850 ssd). This is a screenshot from iotop, which is 5 minutes after a server reboot. Is this normal, or does it look bad? S.M.A.R.T test for both drives shows no problems.

I wouldn't say its normal, but I wouldn't say its not? are you doing something write intensive right now? Is something being loaded into the cache drive?

 

 

No, not writing anything. You can see the total disk write is below 250 kbps. That's whats worries me. Maybe related to this aswell: 

 

Is something actively running off the SSD cache such as a VM or docker?

Yes, 2 VM's (Windows 10 pro) and around 10 dockers.

OK, that's probably it then. You're probably just fine. If you're not noticing any issues like unused disks not spinning down or something, I bet you're just fine.

Oww okay. Well thanks for the help then @Darksurf  Was just worried with so many processes showing 99.99% IO.

I suggest you keep an eye on it if your worried. One way to test would be to stop the dockers and the VMs and check again while the system is idle.