d3m3zs

Thank you! Safe mode helped.
I discovered that the problem was related to one or more of my installed plugins. By rebooting into normal mode and removing plugins based on their last update date, I resolved the issue. In attachment picture I highlighted plugins that I removed.
Although I haven't pinpointed the exact culprit, I suspect 'System Statistics' might be involved.
 
I don`t want to debug it now, because parity sync is running. 
 

I want to say thank you, it seems issue is resolved, now I know how to backup flash drive and which logs can be important.
Solution was - add active cooling to LSI adapter:

I will take a look at my drives in few days to be sure. 

Ok, problem solved:
executed xfs_repair -L /dev/sdf1 repair successfully finished and disk is empty formatted drive to BTRFS and forgot about XFS on non-Array device.