VMware Server 2.0 Essentials. Virtualization Deployment and Management

VMware Server 2.0 Essentials Virtualization Deployment and Management

Contents Chapter 1. What is VMware Server 2.0?... 9 1.1 What is Virtualization?... 9 1.2 Why is Virtualization Important?... 9 1.3 How Does Virtualization Work?... 10 1.4 Software Virtualization... 10 1.5 Shared Kernel Virtualization... 12 1.6 Kernel Level Virtualization... 13 1.7 Hypervisor Virtualization... 13 1.7.1 Paravirtualization... 14 1.7.2 Full Virtualization... 14 1.7.3 Hardware Virtualization... 14 Chapter 2. Installing VMware Server 2.0 on Linux Systems... 16 2.1 Supported Linux Distributions... 16 2.2 VMware Server 2.0 and Unsupported Linux Distributions... 17 2.3 Downloading VMware Server 2.0... 17 2.4 Installing VMware Server 2.0... 18 2.5 Configuring VMware Server 2.0... 18 2.6 Accessing the VMware Server Management Console... 22 Chapter 3. Installing VMware Server 2.0 on Windows Systems... 24 3.1 Supported Windows Versions... 24 3.2 Downloading VMware Server 2.0 for Windows... 25 3.3 Installing VMware Server 2.0 on Windows using the Wizard... 25 3.4 Performing a Command Prompt VMware Server Installation... 27 3.5 Accessing the VMware Infrastructure Web Access Interface... 29 Chapter 4. A Guided Tour of the VMware Server 2.0 Infrastructure Web Access Interface... 30 4.1 Accessing the VI Web Access Management Interface... 30 4.2 The VI Web Access Menu Bar... 32 4.2.1 Application Menu... 32 3

4.2.2 Virtual Machine Menu... 33 4.2.3 Administration Menu... 35 4.3 A Tour of the VI Web Access Interface... 35 4.4 The VI Web Access Workspace in Host Mode... 36 4.5 The VI Web Access Workspace in Virtual Machine Mode... 37 Chapter 5. Officially Supported VMware Server 2.0 Guest Operating Systems... 40 5.1 Unsupported Linux Guest Operating Systems... 40 5.2 Officially Supported Guest Operating Systems... 40 5.2.1 Microsoft Windows (64-bit)... 40 5.2.2 Microsoft Windows (32-bit)... 41 5.2.3 Linux Operating Systems (64-bit)... 41 5.2.4 Linux Operating Systems (32-bit)... 42 5.2.5 Sun Solaris... 43 5.2.6 Novell Netware... 43 Chapter 6. Creating VMware Server 2.0 Virtual Machines... 44 6.1 Accessing the Create Virtual Machine Wizard... 44 6.2 Creating a New Virtual Machine... 44 6.3 Virtual Machine Memory and CPU Settings... 47 6.4 Hard Disk Configuration... 48 6.5 Configuring Virtual Machine Networking... 49 6.6 Configuring a CD/DVD Drive or ISO Image... 50 6.7 Adding a Floppy Disk Drive and USB Support... 51 6.8 Adding Additional Hardware and Creating the Virtual Machine... 52 6.9 Powering On the New Virtual Machine... 53 Chapter 7. Installing and Using the VMware Remote Console Plug-in... 54 7.1 Installing the VMware Remote Console Plug-In... 54 7.2 Accessing the VMware Remote Console... 56 7.3 Entering VMware Remote Console Full Screen Mode... 58 7.4 Exiting from the VMware Remote Console... 59 4

Chapter 8. Creating VMware Server 2.0 Desktop and Web Shortcuts... 60 8.1 Creating a Virtual Machine Desktop Shortcut... 60 8.2 Creating a Web Shortcut... 62 Chapter 9. Understanding and Installing VMware Tools... 65 9.1 An Overview of VMware Tools... 65 9.2 VMware Device Drivers... 65 9.3 VMware Tools Service... 65 9.4 VMware User Process... 66 9.5 VMware Tools Control Panel... 67 9.6 Installing VMware Tools on a Windows Guest... 67 9.7 Installing VMware Tools on a Linux Guest... 70 9.8 Uninstalling VMware Tools... 74 Chapter 10. The VMware Tools Control Panel... 75 10.1 Accessing The VMware Tools Control Panel... 75 10.2 Configuring Host and Guest Time Synchronization... 76 10.3 Miscellaneous Configuration Options... 77 10.4 Device Configuration Options... 78 10.5 VMware Tools Script Configuration... 78 10.6 Shrinking Virtual Disks using the VMware Tools Control Panel... 78 Chapter 11. Working with VMware Tools Scripts and Power States... 79 11.1 Changing Virtual Machine Power State from VI Web Access... 79 11.2 Configuring Virtual Machine Power Options... 79 11.3 Power Controls... 81 11.4 VMware Tools Scripts... 81 11.5 BIOS Setup... 82 11.6 Advanced... 82 11.7 The Default VMware Tools Scripts... 82 11.8 Creating Custom VMware Tools Scripts... 82 11.9 Passing a String from the Host to the Guest... 83 5

11.10 Linux, Solaris and FreeBSD Reboot and Shutdown Commands... 84 Chapter 12. Configuring VMware Server 2.0 Host-Wide Settings... 85 12.1 Host-wide Memory Settings... 85 12.2 Memory Swapping Configuration... 87 12.3 Host-wide Virtual Machine Startup and Shutdown... 88 12.4 Configuring Background Snapshot Settings... 91 Chapter 13. VMware Server Virtual Network Architecture... 92 13.1 VMware Server Virtual Network Configurations... 92 13.2 VMware Server Virtual Network Switch... 93 13.3 VMware Server Virtual Network Adapter (NIC)... 94 13.4 VMware Host Virtual Adapter... 94 13.5 VMware Built-in DHCP Server... 95 Chapter 14. Managing VMware Virtual Networks and Adapters... 96 14.1 Adding a New Virtual Network Adapter to a Virtual Machine... 96 14.2 Removing Virtual Network Adapters... 98 14.3 Modifying Virtual Network Adapter Settings... 98 14.4 Managing VMware Server Host Virtual Adapters... 100 Chapter 15. VMware Server NAT Configuration... 104 15.1 How VMware Server based NAT Works... 104 15.2 Configuring NAT on Windows VMware Hosts... 105 15.3 Configuring NAT on Linux Hosts... 109 15.3.1 [host]... 109 15.3.2 [udp]... 109 15.3.3 [incomingtcp]... 109 15.3.4 [incomingudp]... 110 Chapter 16. VMware Server 2.0 DHCP Configuration... 111 16.1 Static and DHCP IP Address Allocation Ranges... 111 16.1.1 HostOnly Virtual Network IP Addresses... 111 16.1.2 NAT Virtual Network IP Addresses... 112 6

16.2 Configuring the VMware Server DHCP Server on Windows Hosts... 112 16.3 Configuring the VMware Server DHCP Server on Linux Hosts... 115 Chapter 17. Managing VMware Server 2.0 Virtual Disks... 117 17.1 VMware Server Virtual Disk and Device Types... 117 17.2 VMware Server Disk Modes... 118 17.3 VMware Server Virtual Disk Caching Options... 118 17.4 Adding a New Virtual Disk... 118 17.5 Modifying a VMware Server Virtual Disk Configuration... 120 17.6 Enlarging a VMware Server Virtual Disk... 121 17.7 Shrinking a VMware Server Virtual Disk... 121 17.8 Removing a VMware Server Virtual Disk... 122 Chapter 18. Command Line Management of VMware Virtual Disks... 123 18.1 The VMware Virtual Disk Manager Command Line Tool... 123 18.2 Converting Virtual Disks... 123 18.3 Renaming a Virtual Disk... 124 18.4 Creating a Virtual Disk... 125 18.5 Shrinking a Virtual Disk... 125 18.6 Expanding a Virtual Disk... 126 18.7 Defragmenting a Virtual Disk... 126 Chapter 19. VMware Server 2.0 Security - Access, Roles and Permissions... 128 19.1 VMware Server 2.0 Access Controls... 128 19.2 Understanding Privileges, Roles and Permissions... 128 19.3 Creating, Modifying and Removing Roles... 129 19.4 Creating, Modifying and Removing Permissions... 131 Chapter 20. Controlling VMware Virtual Machines from the Command Line with vmrun... 135 20.1 The Basics and Syntax of vmrun... 135 20.2 Performing General Administrative Tasks with vmrun... 137 20.3 Controlling Virtual Machine Power States with vmrun... 138 20.4 Virtual Machine Snapshots with vmrun... 139 7

20.5 Running and Managing Guest Programs with vmrun... 140 20.6 Running Scripts within a Guest... 141 20.7 Using vmrun to Work with Guest Operating Systems Files and Directories... 142 20.8 Capturing a Virtual Machine Screenshot... 144 8

Chapter 1. What is VMware Server 2.0? VMware Server 2.0 is the second release of a virtualization solution provided by VMware, Inc., a division of EMC Corporation. VMware Server is supplied free of charge and is the entry level product of a range of virtualization solutions provided by VMware. 1.1 What is Virtualization? In a traditional computing model, a computer system typically runs a single operating system. For example, a desktop computer might run a copy of Windows XP or Windows Vista, while a server might run Linux or Windows Server 2008. The concept of virtualization, as it pertains to this book, involves the use of a variety of different technologies to allow multiple and potentially varied operating system instances to run concurrently on a single physical computer system, each sharing the physical resources of the host computer system (such as memory, network connectivity, CPU and storage). Within a virtualized infrastructure, a single physical computer server might, for example, run two instances of Windows Server 2008 and one instance of Linux. This, in effect, allows a single computer to provide an IT infrastructure that would ordinarily required three computer systems. 1.2 Why is Virtualization Important? Virtualization has gained a considerable amount of coverage in the trade media in recent years. Given this sudden surge of attention it would be easy to make the assumption that the concept of virtualization is new. In fact, virtualization has been around in one form or another since it was first introduced on IBM mainframe operating systems in the 1960s. The reason for the sudden popularity of virtualization can be attributed to a number of largely unconnected trends: Green computing - So called green computing refers to the recent trend to reduce the power consumption of computer systems. Whilst not a primary concern for individual users or small businesses, companies with significant server operations can save considerable power usage levels by reducing the number of physical servers required using virtualization. An additional advantage involves the reduction in power used for cooling purposes, since fewer servers generate less heat. Increased computing power - The overall power of computer systems has increased exponentially in recent decades to the extent that many computers, by running a single operating system instance, are using a fraction of the available memory and CPU power. 9

Virtualization allows companies to maximize utilization of hardware by running multiple operating systems concurrently on single physical systems. Financial constraints - Large enterprises are under increasing pressure to reduce overheads and maximize shareholder returns. A key technique for reducing IT overheads is to use virtualization to gain maximum return on investment of computer hardware. Web 2.0 - The term Web 2.0 has primarily come to represent the gradual shift away from hosting applications and data on local computer systems to a web based approach. For example, many users and companies now use Google Apps for spreadsheet and word processing instead of installing office suite software on local desktop computers. Web services such as these require the creation of vast server farms running hundreds or even thousands of servers, consuming vast amounts of power and generating significant amounts of heat. Virtualization allows web services providers to consolidate physical server hardware, thereby cutting costs and reducing power usage. Operating system fragmentation - In recent years the operating system market has increasingly fragmented with Microsoft ceding territory to offerings such as Linux and Apple's Mac OS. Enterprises are now finding themselves managing heterogeneous environments where, for example, Linux is used for hosting web sites whilst Windows Server is used to email and file serving functions. In such environments, virtualization allows different operating systems to run side by side on the same computer systems. A similar trend is developing on the desktop, with many users considering Linux as an alternative Microsoft Windows. Desktop based virtualization allows users to run both Linux and Windows in parallel, a key requirement given that many users looking at Linux still need access to applications that are currently only available on Windows. 1.3 How Does Virtualization Work? A number of different approaches to virtualization have been developed over the years, each with inherent advantages and disadvantages. VMware Server 2.0 uses a concept known as software virtualization. This, and the other virtualization methodologies, will be covered in detail in the remaining sections of this chapter. 1.4 Software Virtualization Software virtualization is perhaps the easiest concept to understand. In this scenario the physical host computer system runs a standard unmodified operating system such as Windows, Linux, UNIX or Mac OS X. Running on this operating system is a virtualization application which executes in much the same way as any other application such as a word processor or spreadsheet would run on the system. It is within this virtualization application that one or 10

more virtual machines are created to run the guest operating systems on the host computer. The virtualization application is responsible for starting, stopping and managing each virtual machine and essentially controlling access to physical hardware resources on behalf of the individual virtual machines. The virtualization application also engages in a process known as binary rewriting which involves scanning the instruction stream of the executing guest system and replacing any privileged instructions with safe emulations. This has the effect of making the guest system think it is running directly on the system hardware, rather than in a virtual machine within an application. Some examples of software virtualization technologies include VMware Server, VirtualPC and VirtualBox. The following figure provides an illustration of software based virtualization: As outlined in the above diagram, the guest operating systems operate in virtual machines within the virtualization application which, in turn, runs on top of the host operating system. Clearly, the multiple layers of abstraction between the guest operating systems and the underlying host hardware are not conducive to high levels of virtual machine performance. This technique does, however, have the advantage that no changes are necessary to either host or guest operating systems and no special CPU hardware virtualization support is required. 11

1.5 Shared Kernel Virtualization Shared kernel virtualization (also known as system level or operating system virtualization) takes advantage of the architectural design of Linux and UNIX based operating systems. In order to understand how shared kernel virtualization works it helps to first understand the two main components of Linux or UNIX operating systems. At the core of the operating system is the kernel. The kernel, in simple terms, handles all the interactions between the operating system and the physical hardware. The second key component is the root filesystem which contains all the libraries, files and utilities necessary for the operating system to function. Under shared kernel virtualization the virtual guest systems each have their own root filesystem but share the kernel of the host operating system. This structure is illustrated in the following architectural diagram: This type of virtualization is made possible by the ability of the kernel to dynamically change the current root filesystem (a concept known as chroot) to a different root filesystem without having to reboot the entire system. Essentially, shared kernel virtualization is an extension of this capability. Perhaps the biggest single drawback of this form of virtualization is the fact that the guest operating systems must be compatible with the version of the kernel which is being shared. It is not, for example, possible to run Microsoft Windows as a guest on a Linux system using the shared kernel approach. Nor is it possible for a Linux guest system designed for the 2.6 version of the kernel to share a 2.4 version kernel. 12

Linux VServer, Solaris Zones and Containers, FreeVPS and OpenVZ are all examples shared kernel virtualization solutions. 1.6 Kernel Level Virtualization Under kernel level virtualization the host operating system runs on a specially modified kernel which contains extensions designed to manage and control multiple virtual machines each containing a guest operating system. Unlike shared kernel virtualization each guest runs its own kernel, although similar restrictions apply in that the guest operating systems must have been compiled for the same hardware as the kernel in which they are running. Examples of kernel level virtualization technologies include User Mode Linux (UML) and Kernel-based Virtual Machine (KVM). The following diagram provides an overview of the kernel level virtualization architecture: 1.7 Hypervisor Virtualization The x86 family of CPUs provide a range of protection levels also known as rings in which code can execute. Ring 0 has the highest level privilege and it is in this ring that the operating system kernel normally runs. Code executing in ring 0 is said to be running in system space, kernel mode or supervisor mode. All other code such as applications running on the operating system operate in less privileged rings, typically ring 3. 13

Under hypervisor virtualization a program known as a hypervisor (also known as a type 1 Virtual Machine Monitor or VMM) runs directly on the hardware of the host system in ring 0. The task of this hypervisor is to handle resource and memory allocation for the virtual machines in addition to providing interfaces for higher level administration and monitoring tools. Clearly, with the hypervisor occupying ring 0 of the CPU, the kernels for any guest operating systems running on the system must run in less privileged CPU rings. Unfortunately, most operating system kernels are written explicitly to run in ring 0 for the simple reason that they need to perform tasks that are only available in that ring, such as the ability to execute privileged CPU instructions and directly manipulate memory. A number of different solutions to this problem have been devised in recent years, each of which is described below: 1.7.1 Paravirtualization Under paravirtualization the kernel of the guest operating system is modified specifically to run on the hypervisor. This typically involves replacing any privileged operations that will only run in ring 0 of the CPU with calls to the hypervisor (known as hypercalls). The hypervisor in turn performs the task on behalf of the guest kernel. This typically limits support to open source operating systems such as Linux which may be freely altered and proprietary operating systems where the owners have agreed to make the necessary code modifications to target a specific hypervisor. These issues notwithstanding, the ability of the guest kernel to communicate directly with the hypervisor results in greater performance levels than other virtualization approaches. 1.7.2 Full Virtualization Full virtualization provides support for unmodified guest operating systems. The term unmodified refers to operating system kernels which have not been altered to run on a hypervisor and therefore still execute privileged operations as though running in ring 0 of the CPU. In this scenario, the hypervisor provides CPU emulation to handle and modify privileged and protected CPU operations made by unmodified guest operating system kernels. Unfortunately this emulation process requires both time and system resources to operate resulting in inferior performance levels when compared to those provided by paravirtualization. 1.7.3 Hardware Virtualization Hardware virtualization leverages virtualization features built into the latest generations of CPUs from both Intel and AMD. These technologies, known as Intel VT and AMD-V respectively, provide extensions necessary to run unmodified guest virtual machines without the overheads inherent in full virtualization CPU emulation. In very simplistic terms these new processors provide an additional privilege mode above ring 0 in which the hypervisor can operate essentially leaving ring 0 available for unmodified guest operating systems. 14

The following figure illustrates the hypervisor approach to virtualization: As outlined in the above illustration, in addition to the virtual machines, an administrative operating system and/or management console also runs on top of the hypervisor allowing the virtual machines to be managed by a system administrator. Hypervisor based virtualization solutions include Xen, VMware ESX Server and Microsoft's Hyper-V technology. 15