One of our debian-based Proxmox hypervisors is having issues with high IO load on a Raid1 HDD array, used primarily for the root and home filesystems of the Linux VMs running on top.
We have CollectD-based graphs available and can clearly see a large change in the number of Read operations a few days back. These graphs aren't, however, a way to see what process causes the load.
Is there a tool, similar to iotop or dstat, that could display processes generating the largest load, but only on a specific drive? As the server also has an SSD array under high load, all results from those tools are completely useless.