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Runner Header: Hypervisors

Hypervisors
CIS 512
December 16, 2012

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In today’s world technology has advance in numerous ways. Technology has given the capabilities to receive, fix, and move objects without being present. This is the concept of virtualization. “Virtualization is the creation of a virtual (rather than actual) version of something, such as an operating system, a server, a storage device or network resources”. The virtualization innovation has assisted companies in a positive way, but also can inflict negative wounds to the organization. Virtualization is a proven software technology that is rapidly transforming the IT landscape and fundamentally changing the way that people compute. The 1960s was when virtualization was first deployed by IBM, itts main purpose was to operate mainframe hardware through separating them into virtual machine. In the 1980s and 1990s virtualization was not needed due to the growing numbers of desktop computing and x86 servers. New issues came to rise such as soaring maintenance and managing cost which lead to the creation of virtualization for x86 platform. Virtualization significantly drops general IT costs. Virtualization permits you to run several operating systems on a single computer. In July 2006 Microsoft made public a free Microsoft Virtual PC 2004 which is a windows hosted virtualization program. The latest version is combined with Windows 7 operating system (http://www.infobarrel.com/History_of_Virtualization). Today’s powerful x86 computer hardware was designed to run a single operating system and a single application. This leaves most machines vastly underutilized. Virtualization lets you run multiple virtual machines on a single physical machine, sharing the resources of that single computer across multiple environments.

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Virtualization is a framework or methodology of dividing the resources of a computer into multiple execution environments, by applying one or more concepts or technologies such as hardware and software partitioning, time-sharing, partial or complete machine simulation, emulation, quality of service, and many others (An Introduction to Virtualization).
Virtualization is technology for supporting execution of computer program code, from applications to entire operating systems, in a software-controlled environment. Such a Virtual Machine (VM) environment abstracts available system resources (memory, storage, CPU core(s), I/O, etc.) and presents them in a regular fashion, such that “guest” software cannot distinguish VM-based execution from running on bare physical hardware (Open Kernel Labs).
Virtualization commonly refers to native virtualization, where the VM platform and the guest software target the same microprocessor instruction set and comparable system architectures. Virtualization can also involve execution of guest software cross-compiled for a different instruction set or CPU architecture; such emulation or simulation environments help developers bring up new processors and cross-debug embedded hardware (Open Kernel Labs).
A virtual machine provides a software environment that allows software to run on bare hardware. This environment is created by a virtual-machine monitor, also known as a hypervisor. A hypervisor, also called virtual machine monitor (VMM), is computer software/hardware platform virtualization software that allows multiple operating systems to run on a host computer concurrently. A virtual machine is an efficient, isolated duplicate of the real machine. The hypervisor presents an interface that looks like hardware to the “guest” operating system (An Introduction to Virtualization).
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Virtualization is also a method of partitioning one physical server computer into multiple “virtual” server, giving each the appearance and capabilities of running on its own dedicated machine. Each virtual server functions an s a full-fledged server and can be independently rebooted. The advantage to hypervisor-based replication is that it is virtual machine (VM) aware and that it can replicate from any storage device to any storage device. Even if multiple VMs share the same volume, specific VMs can be selected for replication, greatly simplifying storage setup and minimizing storage capacity requirements at the DR site. This provides the administrator with greater flexibility in selecting storage solutions both locally and in the disaster recovery site. As virtualized environments become larger and more complex, though, IT departments need good management software to track them and keep them patched and up to date. It's much easier to create a new VM than it is to set up a new physical server, so virtualized environments sometimes suffer from the creation of too many VMs, a phenomenon known as VM sprawl Feature Hyper V (R2) VMware (vSphere 5) Distributed resource scheduling - Automatically load balances the virtual machines between hosts No* Yes APIs for array integration - Allows hypervisor to offload common storage tasks to a compatible storage array. No Yes “Storage vMotion” or MS equivalent - Enables the migration of VM disks between storage pools while the VM is powered on No Yes Fault tolerance - Protects critical VMs in the event of a host failure. No Yes Boot from flash - The ESXi hypervisor is a compact OS enabling it to boot from flash memory in the server. This means there is no requirement for mirrored disks or a RAID controller in the hosts. No Yes Memory de-duplication and compression - ESXi supports advanced techniques to take advantage of RAM in each host which would otherwise be wasted.
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This typically allows for a 20% reduction in host/RAM quantity over Hyper- V. No* Yes Site recovery manager - Offers a simple and structured way of migrating VMs between sites in a disaster recovery scenario.
Replication is often an expensive add-on option from storage vendors, plus again it requires the purchase of a second nearly identical system. Even when vendors claim to include replication there is a cost associated with the option (nothing is really “free”). There is the extra profit margin that the vendor makes on the hardware because the software is "included", there is the cost of a second storage system and there is the cost of having to support multiple replication solutions if more than one storage system is present in the data center. By using the replication in the hypervisor, costs are dramatically reduced. There is no extra option to purchase or "value add" to factor in. It simply is there and ready to use.
Again the secondary site can be outfitted with a single more cost effective system to be used as the DR target. Use virtual and physical machines to build a network infrastructure of any degree of complexity, or to create virtual routers or isolate virtual network traffic. The VMs can be either on the same host server or completely different ones. Another useful feature is traffic shaping, in order to limit bandwidth for certain machines or establish a priority system. VMware ESX and ESXi 4.0 are optimized for use with common business applications, such as Oracle Database, Microsoft SQL Server and Microsoft Exchange. Hypervisor is use remotely through a graphical client, using VMware vSphere, or with a command line interface, with VMware Power (PowerCLI). Increasingly, people are using smartphones and tablets for more than business calls:
Hypervisors 6 video conferencing, email, document editing, storage and oral presentations are just a few popular applications. This movement towards portable devices is a direct result of the trend towards enterprise mobility, with distributed workforces and portable workspaces. Security conscious multinational companies prefer to issue approved devices and often explicitly disallow use of corporate phones for personal use and personal phones for corporate use. Furthermore, IT departments are increasingly using enterprise management tools to control mobile devices. Unfortunately, users dislike these policies almost universally: they force the employee to carry smartphones for company use and for personal use. If permitted to use their corporate phone for personal activities, users often lament lack of privacy and device choice. The solution is to 'Bring Your Own' smartphone to the office: allowing employees to choose their favorite device and to use it without privacy concerns whilst enabling the same device to be used for work activities, with enterprise usage fully managed by corporate IT. The independence of the personal and enterprise environments has led some to describe these devices as dual persona. One obvious requirement of a dual persona device is to ensure that cost and features (such as connectivity, graphics and battery life) are not significantly impacted relative to a traditional consumer platform.
Four approaches to dual persona have been commercialized in one form or another: •Dual boot •WebTop •Type-2 hypervisor •Type-1 hypervisor. The dual boot concept has been attempted on a handful of laptops and netbooks over the past few years. One example is Splashtop (www.splashtop.com). In a dual boot scenario, a secondary operating system, typically a scaled down Linux, can be launched in lieu of the main platform operating system (OS). The
Hypervisors 7 scaled down system is typically used only for web browsing, the primary goal being to enable the user to browse within a handful of seconds from cold boot.
The secondary OS resides in separate storage and never runs at the same time as the primary platform OS. In some cases, the lightweight environment executes on a secondary microprocessor (for example, an ARM SoC independent of the netbook's main Intel processor). The secondary OS has good isolation from a security perspective, which both enterprise and consumer appreciate; however, the inconvenience of rebooting and the inability to switch seamlessly between personas has severely limited adoption. Furthermore, because the consumer persona is incapable of much more than simple browsing, it fails to meet the requirement of providing a complete functional replacement of the consumer's desired environment. The WebTop concept also provides a limited browsing environment, independent from the primary user environment.
However, instead of dual boot, the webtop runs as an application on top of the primary OS. One example is Motorola's Atrix 4G smartphone, whose primary consumer persona is as a fully equipped Android phone. The enterprise persona (or webtop) is a desktop flavour Firefox browser launched when the Atrix is connected to an optional dock with keyboard, mouse and screen. Because the enterprise persona is simply an application, it suffers from poor isolation from the consumer persona. Practically every smartphone ever built has been rooted. Rooting is the process by which hackers take advantage of some platform vulnerability, such as a kernel flaw, to illicitly obtain superuser privilege and then use this privilege to 'customize' the device.

Hypervisors 8 In other words, an Android root file system – even the kernel itself – can be changed or replaced completely. From a security perspective, IT security administrators must assume the consumer persona has been commandeered. Protecting the enterprise requires the consumer persona and its potentially malicious software are strongly isolated from the enterprise persona. Similarly, users want assurance that the enterprise cannot observe or access anything on the consumer persona. The webtop approach does not meet this requirement.
Furthermore, the webtop's limited enterprise persona – little more than a web browser – again fails to reach functional equivalence to a full featured platform. While the Atrix does permit the enterprise persona to be connected to a remote desktop, the disconnected user – for instance, on an airplane – is unable to work, defeating the purpose of enterprise mobility. Type 2 hypervisor Type 2 hypervisors are similar to webtops in that the secondary persona runs as an application on top of the primary OS. However, instead of hosting only a browser, the secondary persona is a fully fledged guest OS running within a virtual machine created by the hypervisor application. The hypervisor uses the primary operating system to handle I/O and this virtualization approach meets the requirement of providing complete functional environments for both personas. However, the Type 2 model fails to provide strong isolation. Rooting the primary OS enables the commandeering, data stealing or even destruction of the secondary persona. In addition, numerous hypervisor vulnerabilities have been discovered, allowing information 'escapes' between personas. Type 1 hypervisor Type 1 hypervisors also provide functional completeness of the dual personas. However, because the hypervisor runs on the 'bare metal',
Hypervisors 9 persona isolation cannot be violated by weaknesses in the persona OSs. Thus, a Type 1 hypervisor represents the best approach from both a functionality and security perspective.
However, the hypervisor vulnerability threat still exists, and not all Type 1 hypervisors are designed to meet high levels of security. One particular variant, the microkernel based Type-1 hypervisor, is designed specifically to meet the demanding security requirements of high value enterprises. For example, Green Hills Software's INTEGRITY Multivisor provides strong persona isolation via the INTEGRITY microkernel – the only technology certified to EAL 6+, the highest Common Criteria security level ever achieved for software and deemed appropriate for 'management of classified and other high valued information, whose confidentiality, integrity or releasability must be protected', even in the 'presence of both sophisticated threat agents' where the 'likelihood of an attempted compromise is high'. In addition to isolated virtual machines, the microkernel provides a native, open standard POSIX API for the deployment of lightweight security critical processes, such as device authentication, that cannot be entrusted to a general purpose guest.
Total cost of ownership is the ultimate measure to compare it infrastructure platforms, as it incorporates the purchase and support cost of the platform along with ongoing operational and management expenses. The operational efficiency built into your software stark can greatly affect the bottom line once they have procured and implemented their platform, operation costs for administration and maintenance can easily balloon. A salutation that streamlines and automates routine maintenance tasks can increase uptime and save an organization time and

Hypervisors 10 money. It took significantly less time to complete common administrative tasks with the VMware solution, potentially reducing cost-acquisition operational expense costs. VMware ESXi 3.5 can achieve a significantly higher VM density than Microsoft Hyper-V, allowing users to consolidate more servers on a VMware platform. A higher VM density translates to a lower number of physical servers required to support the virtual infrastructure and also leads to reduced guest OS licensing costs, which tend to be dependent on the number of hypervisor instances in an installation. Finally, a higher VM density can also reduce the cost of management servers and licensing, which with some solutions can be complex and expensive, especially when they are licensed per hypervisor host. Together, these costs outweigh any individual component or hypervisor costs, and paint a picture of total cost of acquisition (www.tanejagroup.com). Marketing hype has convoluted not only the differences between hypervisor architectures, but between overall virtual infrastructure management capabilities as well. As a result, users often have a difficult time understanding what it takes to properly set up a functioning virtual server infrastructure in a real world data center. Though the variation between hypervisors and virtual server infrastructures is seldom apparent in surface-level comparisons, it has an enormous impact upon both Total Cost of Acquisition (TCA) as well as Total Cost of Ownership (TCO).
TCO is often fuzzy and complex territory, but when it comes down to the reality of today’s hard dollars involved in Total Cost of Acquisition, hidden costs simply must be understood.

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To that end, we have carried out this Technology Validation exercise. We will first examine the relative performance of two hypervisors – VMware ESXi and Microsoft Hyper-V – with a series of performance tests. Using our assessment of performance, we will then examine how relative performance contributes to total virtual infrastructure costs, and conduct a comparative assessment of TCA. But first, we’ll discuss how the industry is in need of a lens of simplification with which to view hypervisor selection, and discuss what we consider the best framework for capturing total cost of acquisition – virtual server infrastructure cost per application.

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References
http://www.ok-labs.com/virtualization-and-security/what-is-virtualization. www.principledtechnologies.com/clients/reports/VMware/vsphere5density0811.pdf www.splashtop.com www.tanejagroup.com http://www.virtualization.org/Virtualization/Introduction_to_Virtuaization.html.