Xen Basics A Primer for the CPS 110 Programming Assignments Angela Dalton

Objective To prepare you for the course programming assignments

What is Xen? A virtual machine monitor (VMM) for x86- compatible computers Run multiple instances of OSes simultaneously These are called Guest OSes Provides isolation between Guest OSes Uses Paravirtualization Does not hide virtualization from the Guest OSes OS must be ported to work with Xen

Using Xen in CPS 110 Xen machine: cps210.cod.cs.duke.edu Each team will have an account on cps210 Watch your for info Part of Assignment 1: Get your team’s Linux Guest OS up and running on cps210

The xm Utility Command line utility to control guests Commands to know: xm create xm console xm list xm help

Xen system structure Xen is lowest, most privileged system level Xen hosts multiple Guest OSes (called domains in Xen) running in secure VMs Domain 0 – special privileged management domain Builds other domains and manages their virtual devices The domain you are logging in to when you ssh to cps210.cod.cs.duke.edu

Launching your VM xm create -c configfilename -c flag causes console to attach once VM is created Useful because you’ll see bootup messages Each team has its own config file Edit config file to specify location of linux kernel to boot in your VM

The Xen Commandments Thou shalt not kill another team’s VM If there is a rogue VM causing some problem get in touch with that team and/or Angela and/or a UTA to deal with it Thou shalt not hog memory Config file specifies memory allotted for VM You don’t need much for these projects