(Type I) Hypervisors Lucas Hansen Hypervisors in General ● Virtualize computing systems ● Host and Guest ● Different from emulation ● Instructions execute directly on the hardware ● Two rather different types Type II ● Arguably more widely known ● Programs like VirtualBox and vFusion ● Hypervisors run as a software program within a running operating system ● Host OS still controls 100% of its hardware. ○ It’s process manager schedules the hypervisor just as it does any other process within its scope ○ Guest is only as secure as the host ● Generally Slower ● Used in personal computing environments Type I ● Mainly used in datacenters ● “Bare-Metal Hypervisor” ● To the guests, they serve basically the same function as Type 2 ● Very thin layer between multiple guests and the hardware ● Guests are the only entities running “true” operating systems. ● Sole purpose is to act as a monitor for multiple OS’es ● Qubes OS ○ Previously presented in class History ● 60’s - SIMMON for testing and CP-40/67 for production (Mainframe) ● 70’s-80’ much of the industry development done by IBM in various product lines ○ Support for virtual memory ● 2003 - Project Xen Released ● 2005 - Chipmakers add virtualization support to CPUs ○ Moore’s Law/increase in computing power ○ Proliferation of clustered computing ○ Companies deciding to use services requiring many applications requiring a wide variety of Operating Systems and hardware ● 2008 - VMware ESX(i) ○ Most popular server hypervisor Use Cases ● Resource Pool Sharing ○ Increases hardware utilization ● Reduce Datacenter Footprint ○ Potentially reduce an entire rack of traditional servers into a 1U space ● High Availability Services ○ Ease of scalability allows for more machine instances to be duplicated, adding redundancy to critical systems ○ If one system goes down, no other Guest is affected vSphere Platform (GNU+Linux*) ● VMware flagship enterprise product ● VMware ESXi as it’s hypervisor (Linux*) ● Infrastructure Services ○ Access control ○ Monitoring ○ Provisioning ○ Virtual Filesystems ○ HA *= analogy Sources Virtualization For Dummies https://www.idkrtm.com/history-of-virtualization/ https://searchservervirtualization.techtarget.com/tip/Virtualization-hypervisor-compari son-Type-1-vs-Type-2-hypervisors https://www.qubes-os.org/intro/ https://www.vmware.com/pdf/vsphere4/r40/vsp_40_intro_vs.pdf.