Hello dear Krystof,
Yes you can also include CPU activity in scan_pieces but guy we speak on storage not on IT as Service.
My disks are SATA 7200RPM. I dont think that they are SMR disks. HDD activity that i show on the attached chart is not only piece deleter it’s scan_pieces which permit each time to storj to identify if the pieces are still on the medium through docker container (lsstat).
I opened a previous topic about this scan pieces : Disk activity 100%, Pieces scan to update databases
for the bcache solution given and explained by @xopok it’s on this post : Enable bcache on RaspberryPi 4 4G node 