Insufficient knowledge of operating system internals is my most common reason for passing on an interview candidate. Anyone can learn that you run tool X to fix problem Y. But what happens when there is no tool X, or when you can't even accurately pinpoint the root cause of why "It's sometimes slow."
This will be a no-holds-barred, fury-road-paced review of all major parts of modern operating systems with specific emphasis on what's important for system administrators. It will provide just enough of an academic focus to bridge the "whys" so you can make better use of fiddling with the "whats" on a day-to-day basis. As an added bonus, it will prime you for the following day's "Linux Performance Tuning" tutorial with Theodore Ts'o.
You will learn about process management, scheduling, file system architecture and internals, interrupt management, the mysteries of the MMU and TLB, belady's anomaly, page replacement algorithms and hopefully a bit of networking. In a nutshell, we'll cover 16 weeks of college-level material in a few hours.
Buckle up.