sysfs is a Linux pseudo filesystem that is used to export information, and runtime configuration support from drivers into userspace. By convention (LSB) it's mounted on /sys.

The sysfsutils package contains a library and command line tool (systool) to explore /sys and display and alter current settings. The Debian package at least uses this tool to provide boot time configuration of SysFs values through the /etc/sysfs.conf file.

Also note that some kernel options are still configured through /proc/sys or using sysctl and at boot time through /etc/sysctl.conf. See SysctlNotes for more information.

CategorySystemAdministration, CategoryNotes