ADVANCED SERVER VIRTUALIZATION VMware and Microsoft Platforms in the Virtual Data center phần 4 docx

206  Advanced Server Virtualization Merging Virtual Hard Disks Merging disks allows a child disk to be combined with a parent disk as either an update to the parent or as a new separate and unique disk. To merge a disk, select the Merge with Parent or Merge with New option. After selecting the merge method, if Merge with New was chosen, the Merged Virtual Hard Disk type must be chosen along with the name and location of the new disk fi le. Be careful when merging a disk with a parent. If the parent is set to read-only under NTFS, it must be set back to read/ write permissions. If the parent has any other child disks, upon beginning the merge process with the parent (assum- ing that New was not the option chosen) any children besides the current child being operated on will no longer be able to operate, due to the parent no longer being unmodifi ed. Converting Disk Types Converting Fixed to Dynamic Converting a fi xed disk to a dynamic disk is usually done when a fi xed disk is consuming too much disk space.  e conversion process actually creates a sec- ond virtual hard disk and then copies the contents from the original to the newly created disk.  e newly created dynamic disk is smaller than the fi xed disk.  e caveat is that if the fi xed disk is full, then the dynamic disk will be expanded with data to the same size as the fi xed disk and there will be no space savings. Another method of making sure that the new dynamic disk is the smallest size possible is to use the Virtual Disk Precompactor utility and then compact the dynamic disk to make it the smallest size possible.  e compacting section later on in this chapter describes the recommended steps to make a dynamic disk the smallest size possible. Converting Dynamic to Fixed Converting a dynamic disk to a fi xed disk is commonly used to optimize per- formance of a virtual machine.  e performance increase is very slight, but may be critical in some instances of high utilization.  e penalty for doing this is the fi xed disk will consume the entire amount of space that the dynamic disk may have grown to.  is will make the disk fi le more diffi cult to move and copy due to the increased fi le size. Marshall_AU3931_C012.indd 206Marshall_AU3931_C012.indd 206 4/13/2006 1:38:02 PM4/13/2006 1:38:02 PM Microsoft Virtual Server Advanced Topics  207 It is important to understand, for a brief period of time, both a dynamic and a fi xed disk version will exist on the host system. Before doing this or other types of conversions, adequate disk space must be available or the results could be disastrous. Converting Linked to Dynamic Converting a linked disk to a dynamic disk is used to move data from a physical hard disk into a virtual hard disk.  is can be useful for several reasons including moving a data drive from a physical implementation over to a newly built virtual machine that will be taking over the same function or if a machine needs to be converted from physical to virtual. First, the problems of doing linked disk conversions must be addressed. If a linked disk is mounted as a drive with a drive letter on the host operating system, it cannot be used as a linked disk. A linked disk cannot be the host operating system boot disk. Any disk that is mounted with a drive letter and has fi les that are in use cannot be used or read properly. A linked disk cannot be used from a mapped network drive. Changes to linked disks are changes to the actual physi- cal hard disk, so be forewarned that these changes are permanent. Second, when attempting to convert a disk that is bootable, but has been added as a secondary disk on a host server, the disk will mount.  e conversion can be done, however the problem remains that due to the diff erences in the underlying hardware between the physical machine and the virtual machine, the results of attempting to startup the new virtual hard disk after the conversion is likely to fail.  e only way to avoid this problem is to use a tool, such as the one provided by Microsoft called SysPrep. SysPrep removes all of these drivers and dependencies from the original physical machine and allows windows to do a partial reinstall of the drivers and specifi c confi guration variables to facilitate a clean and properly confi gured operating system. Sysprep is discussed in detail in the Template Guest Operating System Image Concepts section of chapter 24. Converting Linked to Fixed  e same caveats and problems that exist for converting a linked disk to a dy- namic disk exist for converting from a linked disk to a fi xed disk.  e only ex- ception is that a fi xed disk will be the same size as the original linked disk—there absolutely must be enough free disk space in the location where the fi xed disk is to be stored. Marshall_AU3931_C012.indd 207Marshall_AU3931_C012.indd 207 4/13/2006 1:38:02 PM4/13/2006 1:38:02 PM 208  Advanced Server Virtualization Compacting Dynamic Disks Compacting a dynamic disk provides a method of reducing a dynamic disk that has grown larger than desired.  e compacting process eliminates all of the excess space in a virtual hard disk.  is is done by examining the virtual hard disk and fi nding the end of the data being stored on the disk and making the fi le shrink to the end of the data. It is recommended that the Virtual Disk Precom- pactor utility be used to prepare the disk for compacting. If Microsoft Virtual Server 2005 R2 is not available, the Vir- tual Disk Precompactor utility that comes with Virtual PC 2004 Service Pack 1 will operate in the same fashion as the Virtual Disk Precompactor released with Microsoft Virtual Server 2005 R2.  is method is supported by Microsoft. Virtual Disk Precompactor  e Virtual Disk Precompactor, which comes with Microsoft Virtual Server 2005 R2 and Virtual PC 2004 Service Pack 1, is a utility that should be run before running the Disk Compactor process.  e Virtual Disk Precompactor writes a series of zeros (called zeroing out) to all of the empty space inside of the dynamic disk.  is ensures that when the Disk Compactor is run that it will eliminate all of the empty space inside of the dynamic disk thereby making it smaller in size. Before running the Virtual Disk Precompactor, it is recom- mended that the inside of the virtual hard disk be cleaned of any unnecessary fi les and that the virtual hard disk be defragmented. When defragmenting the virtual hard disk, if the Microsoft defragment tool is used, it may be benefi cial to run the tool multiple times to ensure full and complete defragmentation.  ird-party tools such as Executive Software’s Diskeeper and Raxco’s Perfect Disk do an excellent job of defragmentation in a few simple passes and in some cases even in a single pass. If time savings is very important in this process than looking at a third-party tool may be very benefi cial. Once these steps have been followed, run the Virtual Disk Precompactor utility and then use the Compact Virtual Hard Disk function of Virtual Server. Following this process will provide the absolute smallest size dynamic disk that can be obtained. Virtual Networking Virtual networking is often a confusing term when it comes to virtualization. Virtual networks along with virtual hard disks are two of the greatest strengths that virtualization off ers. Virtual networking provides the ability to create and Marshall_AU3931_C012.indd 208Marshall_AU3931_C012.indd 208 4/13/2006 1:38:02 PM4/13/2006 1:38:02 PM Microsoft Virtual Server Advanced Topics  209 manipulate networking hardware inside of a host server by doing it virtually us- ing software and drivers.  ere is a central component to Microsoft’s implemen- tation of virtual networking. It is the critical piece to their Virtual Networking model—the Virtual Switch. Virtual Switches Under Microsoft Virtual Server 2005 R2 there are several networks that are au- tomatically created during the installation process.  ese networks are actually virtual switches that are connected to a physical network adapter. It is important to understand however, that a virtual switch does not have to be connected to a physical network adapter; this will be discussed later in this section. Virtual switching and network confi guration is accomplished through a pro- tocol fi lter driver that is listed in each physical network adapter’s protocol stack on the host as Virtual Machine Network Services. Eff ectively, this provides a method for a virtual switch to interface with the host server’s physical network adapter. Additional networks can also be created and pointed through the fi lter driver to a specifi c network adapter and multiple networks/virtual switches can be attached or share the same physical network adapter. It is important to note that when a virtual switch is connected to a physical network adapter, any virtual machines attached to the virtual switch will be unable to communicate with the host.  is is a security feature designed into Virtual Server (see Figure 12.4). Figure 12.4 Virtual Network and Virtual Switch. Virtual Switch Physical Host Network Card Virtual Machine Network Card Communication between virtual machines and outside through a virtual switch. Connectivity to outside, but not to Host. Virtual Machine Network Card Virtual Machine Network Card Marshall_AU3931_C012.indd 209Marshall_AU3931_C012.indd 209 4/13/2006 1:38:02 PM4/13/2006 1:38:02 PM 210  Advanced Server Virtualization  e inability to communicate from the virtual machine to the host across the virtual network switch was implemented as a security measure to prevent users or malicious code inside of a virtual machine from being able to attack or impact the operating condition of the host server. Network Adapter A single virtual network adapter is automatically installed as part of the virtual machine hardware by default when a virtual machine is confi gured under Vir- tual Server.  is behavior makes sense because nearly all virtual machines will need to communicate with another resource on a network.  ere is a limit to the number of virtual network adapters that can be confi gured inside of a single vir- tual machine, and that limit is four. Under most circumstances, a single virtual network adapter is adequate. Virtual Machines Communicating with the Host It is possible to setup communications between the physical host server and its virtual machines.  is can be accomplished by using the Microsoft Loopback adapter.  e installation of the Microsoft Loopback adapter is quite straight for- ward. Go to the Control Panel and select Add Hardware. Next, select the option to manually add hardware, and pick Network adapters. When prompted for the manufacturer, select Microsoft. In the Network Adapter box, click Microsoft Loopback Adapter and then click Next followed by Finish. Once the Microsoft Loopback adapter has been added, create a new virtual network and attach it to the Loopback adapter.  e Loopback adapter should then be given an IP ad- dress. Now any virtual machines that are attached to the newly created network can be given an IP address on the same subnet as the host server’s Loopback adapter, allowing the virtual machine and the host server to communicate with each other. After the Loopback adapter is installed, its TCP/IP properties should be manually confi gured. If the TCP/IP properties are confi gured to use DHCP, the adapter will eventually use an automatic IP address (169.254.x.x) because the adapter is not actually connected to any physical media and therefore it cannot reach a DHCP server. Virtual Machines Communicating with Each Other Privately Private virtual machine to virtual machine networks can be created to provide a very effi cient and secure network between virtual machines. A private virtual Marshall_AU3931_C012.indd 210Marshall_AU3931_C012.indd 210 4/13/2006 1:38:03 PM4/13/2006 1:38:03 PM Microsoft Virtual Server Advanced Topics  211 machine network is eff ectively attaching virtual machines to a dedicated virtual switch with no outside connectivity.  ere is no limit to the number of virtual machines that can be attached to a virtual switch, provided that they reside on the same physical host.  is provides a great deal of fl exibility when doing testing and troubleshooting of multi-tiered applications. To create a private net- work, simply create a new network under virtual server and do not attach it to any physical network or Loopback interfaces. DHCP Server Another facet of a virtual network is the Dynamic Host Confi guration Protocol (DHCP) server that is built into Microsoft Virtual Server 2005 R2.  e DHCP server can be activated going to the Virtual Networks link in the Virtual Server Administration Website, then clicking on the virtual network to be confi gured located under the Confi gure link. To confi gure the virtual DHCP server, click the DHCP server link. Click the Enabled check box and enter in the desired DHCP server settings. Once all the settings have been entered, click the OK button located in the lower right hand corner.  e virtual DHCP server will only give addresses to virtual network cards on the virtual network.  is behavior is in- tentional by design. If a DHCP server is required to give out addresses to both physical and virtual machines, then it must be a normal DHCP server that is installed in either a virtual machine or on a physical machine located on the physical network. DHCP Server Settings Confi guring the virtual DHCP server is easier in Virtual Server than almost any other DHCP serving application around.  e following is an explanation of the available settings used to properly confi gure the virtual DHCP server. • Network address denotes the base IP address range of addresses managed by this DHCP server. • Network mask is the subnet class that will be used by the DHCP server. • Starting IP address begins the range of IP addresses that the DHCP server will distribute to client virtual machines. • Ending IP address ends the range of IP addresses that the DHCP server will distribute to client virtual machines. • Virtual DHCP server address is the IP address of this virtual DHCP s erver. • Default gateway address will populate the default gateway on each client machine that receives an IP address from the DHCP server. It is the IP ad- dress of a local IP router (gateway) that forwards traffi c beyond this virtual network. Marshall_AU3931_C012.indd 211Marshall_AU3931_C012.indd 211 4/13/2006 1:38:03 PM4/13/2006 1:38:03 PM 212  Advanced Server Virtualization • DNS servers will populate the DNS information inside of each client ma- chine so that they can resolve a domain host name query. • WINS servers will populate the WINS information inside of each client machine. • IP address lease time will determine when a client virtual machine must request a new lease.  e minimum value allowed is 60 seconds. • Lease renewal time indicates when a client virtual machine should attempt to renew its lease from the original DHCP server before it expires.  e minimum value allowed is 30 seconds. • Lease rebinding time decides how long before the client virtual machine should request a lease renewal from any DHCP server on the network in- stead of just the original DHCP server that issued the lease.  e minimum value allowed is 45 seconds. Dynamic MAC Addresses Dynamic MAC addresses are useful for quick testing or when there will be a small number of virtual machines used throughout the entire network.  e rea- son that dynamic MAC addresses are not desirable for large scale deployments is due to the possibility of multiple virtual machines ending up with the same assigned dynamic MAC address. When this occurs, network problems start hap- pening mysteriously throughout the network or some virtual machines begin to behave erratically without any reason.  e solution is to avoid using dynamic MAC addresses all together by utilizing static MAC addresses. Static MAC Addresses Static MAC addresses can ensure that there are never duplicate MAC addresses on the network. It is recommended that a standard be created to allow the cre- ation and uniqueness of static MAC addresses throughout the network. Creat- ing a table or spreadsheet to track static MAC address information is a good way to start out; however if virtual machines are being tied into a physical network, the best way to ensure proper enforcement is to use DHCP on the physical net- work for IP address assignments. By using DHCP and tying the distribution of IP addresses to MAC addresses, it is ensured that there will not be any duplicate MAC addresses or IP addresses.  is is because most DHCP server software will not allow a duplicate MAC address or IP address to be entered into the assign- ment table. A simple way to enhance network security and control over IP addresses is by preventing other IP addresses from being distributed by the DHCP server except to those that have registered MAC addresses within the assignment table. Marshall_AU3931_C012.indd 212Marshall_AU3931_C012.indd 212 4/13/2006 1:38:03 PM4/13/2006 1:38:03 PM Microsoft Virtual Server Advanced Topics  213 Some virtualization platforms support virtual Network Ad- dress Translation (NAT). Microsoft Virtual Server 2005 R2 does not have a function that supports any internal NAT of any kind. However, NAT via a network device on the physi- cal network is supported. Creating a virtual network is simple using the Virtual Server Administration Website. Once logged in, select the section Virtual Networks and choose the Create link. After clicking the Create link, the New Virtual Network Properties page is opened. Creating a Virtual Network or Virtual Switch  e fi rst step is to choose a descriptive name for the virtual network, then decide whether it will be connected to one of the host server’s physical adapters, the Mi- crosoft Loopback adapter (if it has been installed), or not bound to an adapter at all (this will create a virtual machine to virtual machine only network). Next, choose if there are any virtual machines listed that should be attached to the virtual network being created. If there are any further notes about the virtual network, they can be supplied in the notes fi eld. Finally, click the OK button located in the lower right corner of the page. After clicking the OK button, the Virtual Network Properties page of the new virtual network that has been created is now displayed.  is is also the loca- tion where the DHCP confi guration option can be selected. Adding or Removing a Virtual Network Adapter To add or remove a virtual network adapter from a virtual machine under Mi- crosoft Virtual Server 2005 R2, go to the Status page for the specifi c virtual machine that will have the virtual network adapter either added or removed. At the Status page, scroll down to the section labeled Network adapters and click on the link.  e Network Adapter Properties page is now displayed.  is page allows for the removal and addition of virtual network adapters. To add a virtual network adapter, click on the button labeled Add Network Adapter and to remove a virtual network adapter, click on the Remove check box above the network adapter information of the network adapter to be removed, and then click the OK button. Creating a Dynamic or Static MAC Address  ere is another property on the Network Adapter Properties page that off ers some additional fl exibility—the Dynamic or Static MAC address option. To Marshall_AU3931_C012.indd 213Marshall_AU3931_C012.indd 213 4/13/2006 1:38:03 PM4/13/2006 1:38:03 PM 214  Advanced Server Virtualization confi gure a dynamic MAC address, click on the radio button next to the word Dynamic. Dynamic is the default setting for all virtual network adapters in the system. If a static MAC address is desired, click on the Static radio button and type in the desired MAC address. It is important that the MAC address is entered in the exact format as the sample MAC address displayed by default. If this is not done correctly, the confi guration will cause an error to occur and prompt with the correct format to use.  e dynamic MAC address format is six groupings of two hexadecimal numbers separated by dashes, i.e., 32-FF-A3-67-4B-DE. When switching from a dynamic MAC address to a static MAC address, make sure to actually click the radio button next to static. All too often it is assumed that when entering the MAC address in the static text fi eld, the software should be intelligent enough to automatically select the static radio button. Un- fortunately, this is not the case. If you type in a static MAC address but forget to switch the radio button and then click OK, the virtual machine confi guration fi le will not be updated with the new MAC address and it will continue to use a dynamically assigned MAC address. Resource Management Resource management inside of Virtual Server 2005 is limited when compared to VMware ESX Server; however the control over CPU resources is superior to that of VMware GSX server. Microsoft employs a system of granular control over the CPU resources consumed and reserved for virtual machines. Resource management of CPUs is done through the Virtual Server Administration Web- site, under the section titled Virtual Server and the link titled Resource Alloca- tion.  is section provides three variables per virtual machine managed by the system, they are: 1. Relative Weight 2. Reserved Capacity 3. Maximum Capacity For a detailed look into what each of these do and how they eff ect virtual ma- chines, please see chapter 10. It should be noted that to optimize the system, all virtual machines should be given specifi c resource settings and there should always be some capacity left for the host operating system. Performance Optimization  is section describes several recommended hardware, software, and confi gura- tion optimizations that can be applied to Microsoft Virtual Server 2005 R2 Marshall_AU3931_C012.indd 214Marshall_AU3931_C012.indd 214 4/13/2006 1:38:03 PM4/13/2006 1:38:03 PM Microsoft Virtual Server Advanced Topics  215 in order to enable optimum virtual machine performance. Although the rec- ommendations presented here do not have to be used for virtual machines to function, they should be used when deploying virtual machines in a production environment. File System Microsoft Virtual Server 2005 R2 requires the NTFS fi le system on the host; this is due to Virtual Server’s reliance on the fi le system level security for all of the security aspects of Virtual Server. Memory Microsoft Virtual Server 2005 R2 should be given as much memory as possible.  is holds true for the host operating system that the platform is operating on, in addition to being able to provide the virtual machines with as much memory as possible. It is important to realize that with each virtual machine that is add- ed, there is an additional amount of memory used not only by the allocation of reserved memory for the virtual machine, but for management overhead of the Virtual Server application to manage that virtual machine.  e actual amount of each virtual machine’s memory usage can be calculated by taking the amount of memory allocated to the virtual machine in Virtual Server and adding an ad- ditional 32MB. As an example, if there is a virtual machine with 1024MB of memory allocated inside Virtual Server, then the total memory usage by that virtual machine will be 1024MB for the virtual machine and 32MB for Virtual Server’s management overhead, totaling 1056MB of memory. Likewise, if there were ten virtual machines, each assigned 1024MB of memory, then the total memory usage by virtual ma- chines on that host server would be 10,560MB of memory. 10,240MB of memory directly allocated to the virtual machine confi guration, and another 320MB of memory allocated to Virtual Server management over- head. Processor Another important performance optimization is to provide Virtual Server with as much CPU compute power as possible.  is can be achieved by adding pro- cessors, breaking up virtual machines into a balance of high utilization virtual machines along with low utilization machines onto the same server and never combining too many high utilization virtual machines on the same physical host server. CPU cycles are a precious commodity on physical servers running Marshall_AU3931_C012.indd 215Marshall_AU3931_C012.indd 215 4/13/2006 1:38:04 PM4/13/2006 1:38:04 PM [...]... http://go .microsoft. com/fwlink/?LinkID=55830 Microsoft Storage Technologies – iSCSI http://go .microsoft. com/fwlink/?linkid=50522 Unattended Installation Microsoft Virtual Server 2005 R2 supports the ability to be installed from a command-line interface Using the features of the command-line interface installation, an unattended installation of Microsoft Virtual Server can be achieved The Microsoft Virtual Server 2005 R2 installer... Details The primary method of installing Microsoft Virtual Server 2005 R2 from the command line uses Windows Installer technologies along with the msi file that is extracted from the Microsoft Virtual Server 2005 R2 Setup.exe file The msi file is a Windows Installer package Windows Installer is used to install the product from the command-line using the executable Windows Installer file named msiexec.exe The. .. Virtual Server Home Page http://go .microsoft. com/fwlink/?LinkId=28331 Virtual Server Host Clustering Step-by-Step Guide for Virtual Server 2005 R2 http://go .microsoft. com/fwlink/?LinkId=55 644 Windows Server Catalog http://go .microsoft. com/fwlink/?LinkId =43 03 iSCSI Support Microsoft Virtual Server 2005 R2 supports remote storage using the iSCSI protocol when used with Microsoft Windows Server 2003 and. .. process can begin Marshall_AU3931_C0 14. indd 239 4/ 13/2006 1:39:30 PM 240 Advanced Server Virtualization Preparing to Install VMware ESX Server Before starting the VMware ESX Server installation process, the following items and information should be readily available: The VMware ESX Server installation CD-ROM media A valid license key for VMware ESX Server A valid license key for VMware Virtual SMP (only... match the version of Microsoft Virtual Server that is running on the host server Not only do Virtual Machine Additions provide performance enhancements to the guest operating system, but they also provide optimizations in the interface between the virtual machine and VMM layer Virtual Server Management A small increase in performance can be gained on a Microsoft Virtual Server host by reducing the application... network interface can be used for virtual machine networking In fact, if there are only a few virtual machines and the network bandwidth demands are high enough; it can be beneficial to dedicate a network interface to each virtual machine Another alternative is to dedicate only a few network interfaces to specific virtual machines and then use a single remaining shared interface for the remaining virtual. .. use in mission critical enterprise data center environments Marshall_AU3931_C013.indd 235 4/ 13/2006 1:38 :44 PM Marshall_AU3931_C013.indd 236 4/ 13/2006 1:38 :44 PM Chapter 14 Installing VMware ESX Server The basic installation of VMware ESX Server 2.5.2 is covered in this chapter Details such as the physical server s BIOS settings, a discussion on hardware drivers for ESX Server, and the ESX Server installation... another during a node failure The failover ensures that all of the virtual machines that were running on the failed node are quickly brought back up on another node in the cluster It is important to understand that Host Clustering does not cluster the virtual machines, instead it clusters the host servers providing the Microsoft Virtual Server 2005 R2 virtualization platform itself, eliminating the. .. discussed including the Microsoft iSCSI Initiator and Microsoft iSNS (Internet Storage Name Service) The URL is provided below and can also be found on this volume’s Web site, http://vmbook.info/links Using iSCSI with Virtual Server 2005 R2 http://go .microsoft. com/fwlink/?LinkId=55 646 Microsoft iSCSI Software Initiator 2.0 http://go .microsoft. com/fwlink/?linkid =44 352 Microsoft iSNS Server http://go .microsoft. com/fwlink/?LinkID=55830... mode installation of VMware ESX Server 2.5.2 1 Power on the server and insert the VMware ESX Server CD-ROM installation media into the CD/DVD-ROM drive during the server s POST sequence If prompted to press any key to boot from CD-ROM, press any key The server will boot from the CD-ROM and the installation process will begin 2 Installation boot options are shown in Figure 14. 1 Choose the default installation . compacting process eliminates all of the excess space in a virtual hard disk.  is is done by examining the virtual hard disk and fi nding the end of the data being stored on the disk and making the. optimizations in the interface between the virtual machine and VMM layer. Virtual Server Management A small increase in performance can be gained on a Microsoft Virtual Server host by reducing the application. understand that Host Clustering does not cluster the virtual machines, instead it clusters the host servers providing the Microsoft Virtual Server 2005 R2 virtualization platform itself, eliminating