Which I/O controller is the fairest of them all?

An I/O controller is a system component intended to arbitrate access to block storage devices; it should ensure that different groups of processes get specific levels of access according to a policy defined by the system administrator. In other words, it prevents I/O-intensive processes from hogging the disk. This feature can be useful on just about any kind of system which experiences disk contention; it becomes a necessity on systems running a number of virtualized (or containerized) guests. At the moment, Linux lacks an I/O controller in the mainline kernel. There is, however, no shortage of options out there. This article (subscribers only) will look at some of the I/O controller projects currently pushing for inclusion into the mainline.

Full Story (comments: 11)