The kernel mounts a root filesystem. I have been saying that for four posts now. Here is the one with nothing underneath it. Every file in /proc reports zero bytes, du says the whole tree is zero, and yet cat gives you answers. Nothing is stored. The read itself is the work. Open /proc/meminfo and the kernel counts pages right then and hands you a number that did not exist a moment earlier. /sys goes further and lets you write. Echo into the right file and you have changed how the scheduler behaves, no config, no reload. I used the word file for years without noticing how much it was covering for. #Linux #Kernel #SysAdmin #DevOps #procfs #Blog #Thoughts