Hi Squid, thanks for the helpful tips. The docker image file was in fact on an array disk and my libvirt folder was also on a disk. Unfortunate that these don't show up with the Open Files and File Activity plugins. Was able to move my system share to an SSD cache and all is good now. It's worth noting for anyone else reading this if you don't have a redundant cache you might not want to move these files to a cache drive as there is a risk of data loss with a single SSD failure.
