Virtualization Tool Guide 1 of 12 http://virtualization.findthebest.com/guide How to Find Virtualization Tool What is Virtualization? Virtualization is the process of breaking up one or more servers into multiple servers. These virtual servers "think" and "act" like physical servers and can be altered to more efficiently distribute the available resources or the organization's data center. Several virtual servers can live on a single physical server, sharing resources as needed. The benefits of virtualization are vested in the fact that many software applications cannot coexist on the same server using traditional server architecture, which leads to thousands of dollars of underutilized hardware. Virtualization is performed by adding a piece of software to the server that acts as an abstraction layer between the physical servers and the virtual servers (or virtual machines). This abstraction layer is known as a hypervisor. The image below illustrates what a traditional server configuration looks like and how it is adjusted to create a new virtual infrastructure using a VMware hypervisor: Once the virtual servers have been created, they can be treated similarly to a physical server. Under this model, multiple applications can coexist on the same physical server, unaware of each other's presence. Virtualization is a trend in IT management that can lead to great savings for organizations by simply consolidating the resources they already have. 4/30/2014 11:31 AM Virtualization Tool Guide 2 of 12 http://virtualization.findthebest.com/guide There are many factors to consider when choosing a virtualization solution for your data center, including: Architecture of your hardware Licensing method of the software Supported guest/host operating systems Supported host hardware Hypervisor type Virtualization type Key Factors Architecture This is the server architecture with which the virtualization software is compatible. It is very important that the virtualization solution you choose supports the architecture of your servers, whether they are x86 (32 Bit) or x64 (Bit) machines. Furthermore, you should check the hardware compatibility lists for the appropriate virtualization solutions. This information is provided by most vendors, but can also be found on the detail pages of each listing on FindTheBest. x86, x64, Power, SPARC License Describes how the software is licensed to the customer. Virtualization software is either available for purchase (proprietary) or for free with access to the source code (open source) . 4/30/2014 11:31 AM Virtualization Tool Guide 3 of 12 http://virtualization.findthebest.com/guide Open source virtualization software, such as Oracle VM VirtualBox, is available for free and gives users access to the source code. Typically, users of open source solutions should have a great deal of experience with virtualization and its concepts, as well as an understanding of the underlying principles that allow a physical/host server to be virtualized. On the other hand, proprietary virtualization software must be purchased by the user. This software tends to be more polished and will offer a graphical user interface (GUI) that separates the user from the code. Open Source (Free), Proprietary Supported Guest Operating Systems The operating systems that are compatible with the hypervisor or virtualization software. Guest operating systems are those used by the virtual machines within the virtual environment. If you have applications on your virtual machines that can only run on specific operating systems, this is an integral factor to consider. AIX, CentOS, Debian Sarge, Fedora, Free BSD, Gentoo, Mac OS X, Mandrake Linux, MS DOS, Novell Linux Desktop, Novell Netware Server, OpenBSD, openSUSE, Oracle Solaris, Red Hat Enterprise Linux AS, Red Hat Enterprise Linux ES, Red Hat Enterprise Linux WS, Red Hat Linux, Slackware, Small Business Server 2003, Solaris x86 Platform Edition, Sun Java Desktop System, SUSE Linux, SUSE Linux Enterprise Server, Turbolinux Enterprise Server, Turbolinux Workstation, Ubuntu, Windows 2000 Professional, Windows 2000 Server, Windows 7, Windows 8, Windows 95, Windows 98, Windows for Workgroups, Windows Me, Windows NT Server, Windows NT Terminal Server Edition, Windows NT Workstation, Windows Server 2003 Enterprise Edition, Windows Server 2003 Standard Edition, Windows Server 2003 Web Edition, ... Hardware Compatibility It is imperative that your server hardware and virtualization solution are compatible. Most virtualization software vendors offer 4/30/2014 11:31 AM Virtualization Tool Guide 4 of 12 http://virtualization.findthebest.com/guide tools to help you discover the hardware compatibilities of their solution, so make sure to check this before making your final decision. Hypervisor Type Describes whether the hypervisor runs directly on the host operating system (type 1/bare-metal hypervisor) or on a host operating system on the server (type 2/hosted hypervisor). For more information, refer to the Virtualization Software Glossary. Bare-Metal (Type 1) Hypervisor Configuration Bare-metal hypervisors live and operate directly on the host server's hardware. In this scenario, the hypervisor acts as an abstraction layer between the host server and the guest operating systems of the virtual machines. Bare-metal hypervisors usually offer higher performance because they are installed directly on the server hardware. They 4/30/2014 11:31 AM Virtualization Tool Guide 5 of 12 http://virtualization.findthebest.com/guide also tend to support more virtual machines per physical CPUs. VMware ESXi, Citrix XenServer, and Microsoft Hyper-V are examples of type 1 hypervisors. Hosted (Type 2) Hypervisor Configuration Hosted hypervisors live inside a conventional operating system on a host server, and the virtual machines (VMs) live within the hypervisor. Hosted hypervisors are installed like applications, but allow virtual machines to access all of the hardware resources that it can see. Examples of type 2 hypervisors include Oracle VM VirtualBox and VMware Server. Bare Metal (Type 1), Hosted (Type 2) Virtualization Type There are several methods of servers, each of which uses a different configuration of hypervisors, operating 4/30/2014 11:31 AM Virtualization Tool Guide 6 of 12 http://virtualization.findthebest.com/guide systems, and applications. The different types of server virtualization are: full virtualization, paravirtualization, and OS virtualization. Note that OS virtualization can be either hardware assistance or hardware assistance. Full Virtualization Under full virtualization, the hypervisor simulates the server hardware such that unmodified guest operating systems (Windows, Linux, etc.) can coexist on a single server while still operating on their own virtual machines. VMware ESX/ESXi is a hypervisor that uses this type of server virtualization. Hardware-Assisted Full Virtualization Hardware-assisted full virtualization takes advantage of the processing capabilities of the host hardware's processors. Under 4/30/2014 11:31 AM Virtualization Tool Guide 7 of 12 http://virtualization.findthebest.com/guide this model, the hypervisors leverage certain features of powerful CPUs (originally developed by Intel and AMD) to allow guest operating systems to operate in complete isolation. The "rings" in these images reflect the security privilege levels of the system. Ring 3 refers to the privileges at the application level, rings 1 and 2 at device-driver levels, and ring 0 at the kernel or hypervisor level. Ring -1 indicates a level specific to AMD and Intel processors that allows the hypervisor to run computations directly instead of going through the operating system. The efficiency created here is the major benefit of hardware-assisted virtualization. Microsoft Hyper-V, VMware ESX/ESXi, and Citrix XenServer are bare-metal hypervisors that can create a hardware-assisted virtualization infrastructure. Paravirtualization 4/30/2014 11:31 AM Virtualization Tool Guide 8 of 12 http://virtualization.findthebest.com/guide In paravirtualization, the kernel of each guest operating system is modified to recognize that it has been virtualized. The purpose of paravirtualization is to reduce the amount of time the guest operating system spends performing operations that are inherently more difficult in a virtualized environment. VMware ESX/ESXi, Citrix XenServer, and Oracle VM Server are all type 1 hypervisors with paravirtualization capabilities. Operating System Virtualization Operating system virtualization is a virtualization method in which only a single operating system is used on a server (no host and guest relationship). While only one operating system exists, several user spaces (called containers) may exist within this operating system, each with their own finite set of resources allocated to them. Operating system-level virtualization is common in virtual hosting environments where customers may purchase virtual personal servers (VPS), as this is a case 4/30/2014 11:31 AM Virtualization Tool Guide 9 of 12 http://virtualization.findthebest.com/guide where finite resources being allocated to many different servers is particularly useful. Parallels Virtuozzo and Solaris Containers are virtualization software capable of providing operating system virtualization. Full Virtualization, Hardware Assisted Virtualization, Operating System Virtualization, Paravirtualization Management Features These are features of the virtualization software that involve the management of virtualized environments. The function of a hypervisor is not to manage the virtual infrastructure, but to create it. That being said, many hypervisors and virtualization software offer virtualization management capabilities. Adaptive Analytics - Gives software the ability to use past performance to determine the severity of problems and whether admins should be notified of shifts in performance. 4/30/2014 11:31 AM Virtualization Tool Guide 10 of 12 http://virtualization.findthebest.com/guide 12345678901234567891011kjfakjnf.kajwnfkjanw.fjnw.a,jefnaw.,enf.awjnf.,awnef,.jawnefa Anti-Virus - Anti-virus components of the software are often included with hypervisors in order to maintain security within the virtual environment. 123456789012345678 Asset Management - Asset management (or inventory management) involves keeping track of virtual machines and shared resource/hardware inventory, allowing administrators to manage their IT assets. Auto Discovery - Allows the administrator to automatically identify components of the virtual infrastructure when they are connected to the network. Automated Workflows - Automated workflows enable virtualized network administrators to define executable processes that can be used to resolve common issues upon notification. Capacity Planning/Management - Capacity planning/management refers to monitoring capacity trends, forcasting capacity shortages, and alerting administrators of capacity-related issues. Change Reports - These reports model and detail changes to the virtual environments' infrastructure. Chargeback/Showback - The chargeback and showback functionality allows the virtual environment manager to both (showback) how different groups/departments in an organization use IT resources and (chargeback) the groups for the resources they use. Configuration Mapping - This feature involves defining the relationships and configurations of all virtual network/system components in order to create a complete "map" of the virtualized environment. Configuration Snapshots - Configuration backup/restore allows users to save a "snapshot" of a single VM, cluster of VMs, or the entire virtualized network to save a restore point that can be reverted to from future configurations. Dynamic Resource Allocation - Used to allocate and reallocate resources (including processing power, network bandwidth, memory, and storage) as necessary. This feature uses performance metrics in order to achieve the most efficient configuration. Failover - Failover is the automatic transition to a secondary VM or server upon failure of the primary component. This is an important capability for high availability. 4/30/2014 11:31 AM Virtualization Tool Guide 11 of 12 http://virtualization.findthebest.com/guide High Availability - High availability is essentially a "promise" by the software vendor that a prearranged level of service and availability of applications in the virtual environment can be maintained. This can be delivered through robust system design and a plan for the occurrence of faults and failures. Live Migration - This feature provides users with the ability to move the location of a virtual machine or its resources without powering down the system. As a result, organizations can maintain operation of their applications during the restructuring of their virtual infrastructure. Maintenance Mode - Maintenance mode allows administrators to perform maintenance on host servers by temporarily migrating guest virtual machines to other servers in the environment. Multiple Host Resource Pools - Multiple host resource pools aggregate all physical server resources within the virtualized environment into one shared pool. This pool can be accessed by all VMs in the network, assuming compatibility between servers. P2V Conversion - P2V, or physical to virtual, conversion involves copying the configuration of an existing physical server and replacing it with a virtual machine that matches the configuration and capabilities of the original. Performance Metrics - Performance metrics allow users to monitor the health of their system by using hard data regarding bandwidth, packets per second, latency, and more. Performance Reports - Performance reports summarize the virtual network's health for administrators. More specific reports about individual metrics, such as bandwidth and packet loss, may be available in various hypervisors. Power Management - Power management is performed by controlling the way that hardware components deliver power and by redistributing VM resources for load balancing. Real Time Alerts - These alerts send notifications to adminstration as soon as faults or failures are detected. Shared Resource Pools - Shared resource pools split-up the resources of a physical server among the virtual servers living on it, creating virtualized storage, memory, CPU, and networks. Storage Migration - Provides the ability to move a single VM's or group of VM's storage from one location within the virtualized environment to another. 4/30/2014 11:31 AM Virtualization Tool Guide 12 of 12 http://virtualization.findthebest.com/guide Thin Provisioning - Used to conserve virtual machine resources, the thin provisioning feature provides the VMs with resources, but only enough to allow the machine to perform its operations at the time of execution. Virtual Firewall - Virtual firewalls may come in several forms, but all offer the same functionality as a common firewall, including capabilities like packet filtering and monitoring. VM Backup/Restore - VM backup/restore lets admins make backup copies of a virtual machine's configuration and stored data, which can later be used to restore a failed virtual machine. VM Cloning - VM cloning allows admins to make cloned copies of virtual machines. These clones can be used in the same manner for scaling operations or as templates for different variations. VM Migration - VM migration is the ability to move virtual machines from one host server to another. What to Watch for in Virtualization Tool Level of Performance Administrators should be aware of the performance implications that virtualization will have on their environment. Server consolidation is often the goal of virtualization because it can save organizations time and money, but if the performance of the system degrades as a result, then perhaps server consolidation isn't the best route. It is therefore important to monitor changes in performance as the virtual landscape evolves. 4/30/2014 11:31 AM