I've been having issues lately with Debian Jessie having insanely high disk I/O. My iowait was at between 15 and 30%, disk utilisation was permanently at 100% - my poor HDD! More importantly, it made the machine pretty unresponsive if I needed to run VMs, editor and browser at the same time. Not the performance I expect from an i7!
After some investigation (mainly using iostat and ps -eo), it appeared to be programs prefixed with tracker- that were the culprits. The information I found about Tracker made it sound pretty nifty, but definitely not a fixed requirement for using Gnome. I don't really use the file search features of the Gnome overlay anyway, and I don't tend to search for files using the UI either - so I figured it's probably safe enough to disable it and see how things go.
To disable it, you will want to run the tracker-properties application. You can either type that into a terminal, or type "tracker" into the overlay, and select Search & Indexing. I unchecked the following options:
- Indexing: Monitor file and directory changes
- Indexing: Enable when running on battery
- Indexing: Enable for initial data population
- Locations: All of them
- Control: Index content of files found (this is most likely to have been the issue, as I have a number of large VMs on this partition)
- Control: Index numbers
After applying these changes, I opened it back up and went to the System tab. This page allows you to remove all old indexed data. I chose to do so, but I don't think it's likely this will achieve much.
Almost immediately after making these changes, my disk spun down, my computer started being responsive again, and I could get back to work in peace!
That's all for today, I just wanted to post this in case it helps anybody else who's experiencing similar issues.