When you are in single user mode there is only one way to login to a Linux machine, from the first virtual console. It also causes problems when you try to shut the machine down. Without it you can't perform any management tasks at all. Reboot your system. The kernel for your Linux computer has been accidentally deleted.
Exercises Find out where kerneld is launched from.
Find out where your kernel image is located and how large it is. Modify the kernel so that the maximum number of tasks it can run is 50. Compile this kernel to a floppy disk. See how long it takes to use all these processes up. Recompile your own kernel, including only the components you need.