Some of the configuration tools of the Linux NET-2 and NET-3 release rely on the /proc filesystem for communicating with the kernel. This interface permits access to kernel runtime information through a filesystem-like mechanism. When mounted, you can list its files like any other filesystem, or display their contents. Typical items include the loadavg file, which contains the system load average, and meminfo, which shows current core memory and swap usage.
To this, the networking code adds the net directory. It contains a number of files that show things like the kernel ARP tables, the state of TCP connections, and the routing tables. Most network administration tools get their information from these files.
The proc filesystem (or procfs, as it is also known) is usually mounted on /proc at system boot time. The best method is to add the following line to /etc/fstab :
# procfs mount point: none /proc proc defaults
The procfs is now configured into most kernels by default. If the procfs is not in your kernel, you will get a message such as: mount: fs type procfs not supported by kernel. You will then have to recompile the kernel and answer “yes” when asked for procfs support.