Added RAID warm-up

Misc/Warm-Ups/raid.tex

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+% https://git.betalupi.com/Mark/latex-packages
+% use [nosolutions] flag to hide solutions.
+% use [solutions] flag to show solutions.
+% Last built with version 1.1.0
+\documentclass[
+	nosolutions,
+	singlenumbering,
+	nopagenumber
+]{ormc_handout}
+
+\usepackage{tikz}
+
+\begin{document}
+
+	\maketitle
+		{The Sysadmin's Warm-Up}
+		{Prepared by Mark on \today}
+
+
+	Most of you have seen a hard drive. Many have touched one, and a lucky few have poked around inside one. These devices have two interesting properties:
+
+	\begin{enumerate}
+		\item They hold valuable data
+		\item They eventually fail
+	\end{enumerate}
+
+	Needless to say, this is a problem. \\
+	We need to design a system that allows hard drives to fail without data loss.
+
+	\definition{}
+	You can think of a hard drive as a long string of bits. \\
+	Assume all hard drives can store 1 TiB of data.
+
+	\begin{center}
+	\begin{tikzpicture}
+
+		\node[above] at (1/2, 0) {Drive A};
+		\draw (0cm, 0cm) -- (0cm, -3cm);
+		\draw (1cm, 0cm) -- (1cm, -3cm);
+		\foreach \i in {0,...,-6} {
+			\draw (0cm,\i cm / 2) -- (1cm ,\i cm / 2);
+		}
+
+		\node at (1/2, - 1 / 4) {1};
+		\node at (1/2, - 3 / 4) {1};
+		\node at (1/2, - 5 / 4) {0};
+		\node at (1/2, - 7 / 4) {...};
+		\node at (1/2, - 9 / 4) {1};
+		\node at (1/2, -11 / 4) {0};
+
+
+		\node[above] at (5/2, 0) {Drive B};
+		\draw (2cm, 0cm) -- (2cm, -3cm);
+		\draw (3cm, 0cm) -- (3cm, -3cm);
+		\foreach \i in {0,...,-6} {
+			\draw (2cm,\i cm / 2) -- (3cm ,\i cm / 2);
+		}
+
+		\node at (5/2, - 1 / 4) {0};
+		\node at (5/2, - 3 / 4) {1};
+		\node at (5/2, - 5 / 4) {0};
+		\node at (5/2, - 7 / 4) {...};
+		\node at (5/2, - 9 / 4) {0};
+		\node at (5/2, -11 / 4) {1};
+	\end{tikzpicture}
+	\end{center}
+
+	\problem{}
+	Suppose we have two hard drives. How can we arrange our data so that...
+	\begin{enumerate}
+		\item We can store 1 TiB of data
+		\item We lose no data when any one drive fails
+	\end{enumerate}
+
+	\vfill
+
+	\problem{}
+	Suppose we have three hard drives. How can we arrange our data so that...
+	\begin{enumerate}
+		\item We can store 2 TiB of data
+		\item We lose no data when any one drive fails
+	\end{enumerate}
+
+	\vfill
+
+	\problem{}
+	Suppose we have five hard drives. How can we arrange our data so that...
+	\begin{enumerate}
+		\item We can store 3 TiB of data
+		\item We lose no data when any two drives fail
+	\end{enumerate}
+
+	\vfill
+
+	\problem{}
+	Can you write a general solution to this problem?
+
+	\vfill
+\end{document}