systemd iocost.conf 5 iocost.conf Configuration files for the iocost solution manager /etc/systemd/iocost.conf /etc/systemd/iocost.conf.d/*.conf This file configures the behavior of iocost, a tool mostly used by systemd-udevd8 rules to automatically apply I/O cost solutions to /sys/fs/cgroup/io.cost.*. The qos and model values are calculated based on benchmarks collected on the iocost-benchmark project and turned into a set of solutions that go from most to least isolated. Isolation allows the system to remain responsive in face of high I/O load. Which solutions are available for a device can be queried from the udev metadata attached to it. By default the naive solution is used, which provides the most bandwidth. All options are configured in the [IOCost] section: TargetSolution= Chooses which I/O cost solution (identified by named string) should be used for the devices in this system. The known solutions can be queried from the udev metadata attached to the devices. If a device does not have the specified solution, the first one listed in IOCOST_SOLUTIONS is used instead. E.g. TargetSolution=isolated-bandwidth. udevadm8, The iocost-benchmarks github project, The resctl-bench documentation details how the values are obtained