mcse exam 70-293 planning and maintaining a windows server 2003 network infrastructure phần 7 ppsx

Hot Spare Drives Another important feature to consider is the use of hot spare drives. Most modern, fault-tol- erant disk controllers support the use of additional hard drives that wait for an existing drive in an array to fail.When the controller determines that a drive has failed, it activates the hot spare drive and uses it to replace the failed drive in the array.The data that was pre- sent on the failed drive is re-created on the hot spare drive by the fault-tolerant controller, not Windows. In this way, an array may operate for a brief time in a decreased availability state, but will not require attention from an administrator to recover from that state. Server Fault-Tolerance Solutions The server is our final point of consideration for fault-tolerance. Our focus in this section is on the server system itself, not on the workload or the services it provides.There are two basic methods for introducing fault-tolerance on a server: hardware redundancy and virtual- ization (called clustering). Modern server hardware is designed around increasing performance and reliability. Higher-end (more complicated and expensive) servers often include many built-in redun- dancy features. It is possible to find servers that support spare RAM and CPUs, redundant power supplies and cooling fans, built-in hardware RAID support, and many other features integrated into the basic system. In addition, many components in modern higher-end www.syngress.com 624 Chapter 8 • Planning, Implementing, and Maintaining a High-Availability Strategy Figure 8.67 RAID 0+1 Data Stripe Data Stripe Mirror Stripe Mirror Stripe Controller Server RAID Level 0 + 1 (Mirroring Plus Striping) 255_70_293_ch08.qxd 9/10/03 1:44 PM Page 624 servers are hot-swappable, meaning the power does not need to be turned off in order to remove or change the component. Another hardware component that is often overlooked but is easily acquired and imple- mented is a redundant power source. Ideally, you want duplicate power sources all the way back to duplicate utility companies, but that is usually not possible.What is possible is the installation of an Uninterruptible Power Supply (UPS) and the software to communicate with it. A UPS is basically a large battery, although this term is sometimes also used to refer to a generator.Your equipment plugs into the UPS, and the UPS plugs into utility power. If utility power is cut, the UPS continues to power your equipment. Most often, a UPS is used to provide power long enough for a proper system shutdown. Size a UPS by the amount of power it must provide and the length of time needed to run when on battery. The more equipment on a UPS or the longer the required runtime, the “larger” the UPS must be. In very large environments, consider multiple UPSs operating in parallel (never “daisy-chain” UPSs) and possibly a backup generator. EXAM WARNING In addition to your servers, you may also need to have your switches and hubs, a monitor, and other equipment plugged into a UPS. Many UPS systems come with software that uses the network to notify servers that power has been lost. If the network hardware does not have power, servers will not receive these messages. As a result, they will not know they need to shut down. In addition, you may want to leave hardware plugged in that allows you to interact with the server during power outages. That will be hard to do without a monitor. Server virtualization refers to a method used to reduce the dependence of the services provided by a server on the hardware it runs on. Server clusters are used for this purpose. Server clusters are discussed in Chapter 9. www.syngress.com Planning, Implementing, and Maintaining a High-Availability Strategy • Chapter 8 625 255_70_293_ch08.qxd 9/10/03 1:44 PM Page 625 Summary of Exam Objectives Windows Server 2003 often performs reasonably well in its default configuration, but insuf- ficient memory, CPU, disk, or network resources can reduce performance to an unaccept- able level. Proper tuning and allocation of these resources will ensure adequate performance. Proper configuration of the server’s page files can improve performance. Regular use of the Disk Defragmenter utility will ensure that your file systems do not become a bottleneck for read and write operations. Use efficient and intelligent network adapters to handle some of the processing load and reduce the overall impact communica- tions have on the system. The System Monitor utility can be used to monitor various counters present in the system.These counters display real performance information about what is occurring in the system. Some counters can display statistics as percentages, others as cumulative counts of events, and others as immediate absolute values. System Monitor can be used to view cur- rent activity in the system or to view data from log files. A properly developed baseline can help in planning for increased growth and in identi- fying resources that are being overutilized. A baseline provides a mechanism for identifying what normal operating conditions are for a server.The baseline acts as a reference for trou- bleshooting performance issues. The operating system and some applications record events in numerous event log files. The events in these files are always in the same format and can be viewed, searched, and monitored to determine if a system is functioning properly. Entries in the event logs indi- cate the severity or nature of the events. Security auditing can be enabled and security- related events captured in the event logs.The logs themselves can be archived to create a historical record of a server’s activities. Backing up data is a must to ensure system availability. Only user accounts with ele- vated user rights can perform backups or restores. Different methods (normal, differential, and incremental) for performing backups are available to accomplish different objectives. Backups can be performed to tape drives, network shares, or local disks, but not writable or read-writable CD-ROMs or DVD-ROMs. Some services like DHCP,WINS, and DNS may have special considerations or config- uration issues that need to be addressed before backups are performed. Clustered server disks also require special consideration for backups, and the new Volume Shadow Copy fea- ture assists in creating backups of open files. The Windows Backup Utility can be run either as a Wizard or in Advanced Mode.The Wizard works in most situations and steps you through the process of creating or restoring a backup.The Advanced Mode gives you access to the more powerful options of the utility and lets you fine-tune your backups.The Backup Utility also lets you schedule backup ses- sions, so that you can create a relatively simple and regular backup process. The new ASR feature of Windows Server 2003 simplifies the process of re-creating a failed server installation.The ASR process replaces the older ERD process used in previous versions of Windows. Proper planning and preparation must be completed before ASR can www.syngress.com 626 Chapter 8 • Planning, Implementing, and Maintaining a High-Availability Strategy 255_70_293_ch08.qxd 9/10/03 1:44 PM Page 626 be used to restore a system, and performing an ASR restore should be the last resort. An ASR restore requires a floppy diskette drive to be present in the server, but one is not required to create an ASR backup. The proper use of fault tolerance will mean that services will continue to be provided even when something breaks down. Redundancy in hardware, software, and communica- tions ensures a reliable environment.The use of redundant network interfaces and proxy servers will ensure reliable communications. Using disk RAID arrays for the storage of applications and data will help prevent downtime due to a hard drive failure and may also be used as a performance enhancer. Using redundant components to help cool your server and provide power when the utility power fails will ensure your server operates in adverse conditions. Exam Objectives Fast Track Understanding Performance Bottlenecks  RAM is the one resource that most often becomes a performance bottleneck.  A good rule of thumb is that more RAM is better.  Virtual memory uses hard disk space to expand the apparent memory available in the system. Performance decreases as virtual memory on the disk is heavily used.  The processor is the brain of the computer. A computer can have multiple processors.  Disk controller technology and the use of RAID determines how fast data can be read from or written to disk.  Defragmenting a file system can improve read and write performance.  Running multiple network protocols decreases overall network performance.  Modern NICs can offload some of the communication processing overhead from the CPU to the NIC, which can increase system performance.  The use of IPSec can greatly increase the security of information as it travels on the network. Using appropriate NICs to offload IPSec processing can improve system performance.  Full-duplex communication is desired for servers. Switches are typically required to support full-duplex communications.  System Monitor displays information collected by counters that let you examine the performance of your system. Counters are installed by default by the operating system and some applications. www.syngress.com Planning, Implementing, and Maintaining a High-Availability Strategy • Chapter 8 627 255_70_293_ch08.qxd 9/10/03 1:44 PM Page 627  Baselining is used to determine the average operating parameters of your system so that variations can be detected.  Monitoring a large number of counters can impact system performance. Monitor only the necessary counters.  Information about various events that occur in the system is collected in a number of event log files, which can be viewed using the Event Viewer utility.  Event Viewer can be used to search the logs and filter out events you do not wish to examine. Planning a Backup and Recovery Strategy  Data backup is an essential part of a high-availability strategy.  Many things can cause loss of data—from hardware and software problems to human factors.  Good procedures are an indispensable part of a backup and restore strategy.  The Windows Backup Utility is used to perform backups and restores, as well as to create ASR sets.  Specific user rights and permissions are required to perform a backup or restore.  Several different backup types exist, including normal (full), copy, differential, and incremental.  Backup types are most effective when used in combination.  Volume Shadow Copy is a new feature in Windows Server 2003 that allows the Windows Backup Utility to back up open files.  Different applications and components of the operating system may have specific needs for either backup or restore. Planning System Recovery with ASR  ASR is a new feature of Windows Server 2003 that assists in the rapid re-creation of a server after a major failure.  ASR is a last-resort option. Booting into Safe Mode and the Last Known Good mode should be tried before attempting an ASR restore.  ASR sets are created from the Windows Backup Utility.  ASR sets consist of a floppy disk and media containing the data on every partition or volume that contained system components. www.syngress.com 628 Chapter 8 • Planning, Implementing, and Maintaining a High-Availability Strategy 255_70_293_ch08.qxd 9/10/03 1:44 PM Page 628  A floppy diskette is required to perform an ASR restore.The diskette contains files that describe the disk identities and structure of the system being restored.  An ASR restore requires the ASR backup media, the ASR diskette, and the original Windows Server 2003 media. Planning for Fault Tolerance  Fault tolerance allows for components of a system to fail while the system continues to function.  Fault tolerance is achieved through a combination of redundancy, efficient load distribution, proper planning, proper procedures, and training.  Five nines refers to a system that is available 99.999 percent of the time.  Network interfaces can be made fault tolerant by configuring multiple NICs for failover or load-balanced operation.  Using multiple Web and proxy servers increases availability.  Use of RAID technology can reduce or eliminate downtime caused by disk drive failure.  Several RAID levels exist. Each RAID level is suitable for a specific type of use.  Modern servers often have built-in redundancy, increasing their reliability.  A UPS can prevent or reduce the downtime caused by a power failure. www.syngress.com Planning, Implementing, and Maintaining a High-Availability Strategy • Chapter 8 629 255_70_293_ch08.qxd 9/10/03 1:44 PM Page 629 Q: What is the best way to ensure a server has enough memory to operate acceptably? A: Install more than the minimum amount of RAM. Q: What is using part of a server’s hard disk as an expansion of memory called? A: Virtual memory. Q: What is the file that is used for virtual memory called? A: The paging file. Q: What does a multiprocessing system contain? A: More than one CPU. Q: What are the three most common disk interfaces? A: ATA, SCSI, and Fibre Channel. Q: What happens when a data packet crosses a router from a network with a large packet size to a network with a smaller packet size? A: The router re-creates the original packet as multiple smaller packets and forwards them to their destination. Q: What devices can the Windows Backup Utility use for performing backups? A: Any device supported by the Windows Server 2003 operating system as having remov- able and writable media.Tape devices are the most common. Q: Can ASR be used to completely restore a failed system? A: No, the purpose of ASR is to re-create the operating system. Additional restores of data and applications are required for a full system restore. Q: Why is RAID 5 not recommended for write-intensive situations? A: Every time data is written to a RAID 5 array, the parity block must be recalculated. www.syngress.com 630 Chapter 8 • Planning, Implementing, and Maintaining a High-Availability Strategy Exam Objectives Frequently Asked Questions The following Frequently Asked Questions, answered by the authors of this book, are designed to both measure your understanding of the Exam Objectives presented in this chapter, and to assist you with real-life implementation of these concepts. You will also gain access to thousands of other FAQs at ITFAQnet.com. 255_70_293_ch08.qxd 9/10/03 1:44 PM Page 630 Understanding Performance Bottlenecks 1. You have been tasked with the implementation of enhancing the security of your net- work and have been allocated a modest budget to accomplish the task.You decide to implement IP Security (IPSec) between your three Windows Server 2003 servers and your Windows 2000 Professional and Windows XP Professional workstations. As the implementation proceeds, you begin hearing reports that the network does not seem as responsive.You confirm that performance has decreased.What can you do to return performance to the previous level and still accomplish your objectives? A. Remove IPSec from the workstations, leaving the servers configured with IPSec. B. Remove IPSec from the servers, leaving the workstations configured with IPSec. C. Add NICs to your servers and configure the cards for load balancing. D. Purchase new NICs that support IPSec on the NIC. 2. You have inherited the responsibility of supporting a server from a previous adminis- trator.The system has dual 1 GHz CPUs, 2048MB of RAM, and a dual-channel caching hardware RAID controller with sixteen 18GB hard drives configured as a RAID 5 array.The system has been running an important SQL database for some time, but over the last few weeks, responsiveness has decreased as more people have been accessing the SQL databases.Your part-time SQL administrator has told you that recent database growth is not the culprit.The databases have been consistently using between 40 and 45 percent of the available disk space.You have been asked to resolve this problem.What can you do to increase the responsiveness of the SQL database? A. Install more RAM in the server. B. Change the RAID array to a RAID 0+1 configuration. C. Change the RAID array to a RAID 0 configuration. D. Increase the cache size on the array controller. www.syngress.com Planning, Implementing, and Maintaining a High-Availability Strategy • Chapter 8 631 Self Test A Quick Answer Key follows the Self Test questions. For complete questions, answers, and explanations to the Self Test questions in this chapter as well as the other chapters in this book, see the Self Test Appendix. 255_70_293_ch08.qxd 9/10/03 1:44 PM Page 631 3. You have recently purchased a new single-CPU, Intel Xeon-based server.This hard- ware will be used to run a multithreaded CPU-intensive application. How can you ensure that the application performs at its best on the hardware provided? A. Turn on hyperthreading. B. Add a second CPU. C. Boost the processing priority of the applications threads. D. Disable hyperthreading. 4. Your server seems slow to respond to file requests from drive D: at times.You have examined the system with Performance Monitor, and the counter LogicalDisk:Current Disk Queue Length for the D: instance consistently varies between 8 and 20 during these periods of slow response. Drive D: resides on an external, 14-slot disk array with 4 slots populated with hard drives. How should you resolve this problem? A. Defragment drive D:. B. Add more memory to the system to increase file-caching efficiency. C. Add more physical drives to the external array; either expand drive D: across the new drives or create another drive and move some heavily accessed files from drive D: to the new logical drive. D. Add processors or turn on hyperthreading. 5. You have recently purchased and installed two new name-brand servers.The servers are identical in all respects, except that one server has a single CPU and the other has two.The single-CPU system will be used for basic file and print services, and the dual-CPU system will be used for running Microsoft Exchange Server. Both systems respond adequately.While developing a performance baseline, you notice that the dual-CPU system seems to be experiencing more interrupts per second than the other server.What should you do to resolve this increased level of interrupts? A. Do nothing.This is a peculiarity of Microsoft Exchange Server. B. Increase the communication buffers on the multiple-CPU server’s NIC. C. Remove the second CPU from the dual-CPU system. D. Do nothing.This is normal for a multi-CPU system. Planning a Backup and Recovery Strategy 6. You have been asked to develop a backup strategy for your company’s three Windows Server 2003 servers.You have been told that the primary objective is to have the sys- www.syngress.com 632 Chapter 8 • Planning, Implementing, and Maintaining a High-Availability Strategy 255_70_293_ch08.qxd 9/10/03 1:44 PM Page 632 tems up and running again as quickly as possible should a disaster occur.To accom- plish this goal, initial funds have been allocated and, if necessary, ongoing funds will be made available.What backup strategy should you adopt? A. Full backups nightly to a tape drive installed in each server B. Full backups nightly to a single, centralized tape drive C. Full backups weekly, with daily differential backups to a tape drive installed in each server D. Full ASR backups nightly 7. You have been asked to develop a backup strategy for your company’s three Windows Server 2003 servers.You have been told that the primary objective is to minimize the ongoing cost of performing backups.To accomplish this goal, you have been given a modest budget.What backup strategy should you adopt? A. Full backups monthly, differential backups on the weekends, and incremental backups daily to a tape drive installed in each server B. Full backups monthly, differential backups on the weekends, and incremental backups daily to a single, centralized tape drive C. Incremental backups daily to a single, centralized tape drive D. Periodic full backups and daily incremental backups to a single, centralized tape drive 8. You have been asked to develop a backup strategy for your company’s three Windows Server 2003 servers.You have been told that the primary objective is to minimize the time required for performing backups on regular business days.You do not have the use of any advanced storage technology, and an older application on the server requires you to shut down the application and disable Volume Shadow Copy to get a successful backup.To accomplish this goal, you have been given a sufficient budget. What backup strategy should you adopt? A. Full backups on the weekends and incremental backups daily to a tape drive installed in each server B. Full backups monthly and differential backups daily to a single, centralized tape drive C. Incremental backups daily to a single, centralized tape drive D. Periodic full backups and daily incremental backups to a single, centralized tape drive www.syngress.com Planning, Implementing, and Maintaining a High-Availability Strategy • Chapter 8 633 255_70_293_ch08.qxd 9/10/03 1:44 PM Page 633 [...]... circumstances require an application to be operational more consistently than standard hardware would allow Databases and mail servers often have this need.What if it were possible to have more than one server ready to run the critical application? What if there were a software component that automatically managed the operation of the application so that, if one server experienced a failure, another server. .. Nodes A and B are configured as a failover pair, and nodes C and D are also a failover pair Assorted virtual servers are active and are spread among the nodes Figure 9.5 N-Node Failover, Initial State Initial State Public Network Failover Pair AB Virtual 1 Failover Pair CD Virtual 4 Virtual 5 Virtual 2 Virtual 6 Virtual 3 Virtual 8 Virtual 7 Node A www.syngress.com Node B Node C Node D 255 _70 _293_ch09.qxd...255 _70 _293_ch08.qxd 634 9/10/03 1:44 PM Page 634 Chapter 8 • Planning, Implementing, and Maintaining a High-Availability Strategy 9 Your company uses a well-known and respected third-party backup utility for all of its servers.You are adopting Windows Server 2003 early after its release and have upgraded a number of servers to the operating system.You have high hopes about improving backup performance... the release of Windows 2000 Advanced and Datacenter Server Editions Server clusters were simpler to create, and more applications were available In addition, some publishers began to make their applications “cluster-aware,” so that their applications installed and operated more easily on a server cluster Now with the release of Windows Server 2003, we see another level of improvement on the server clustering... Chapter 9 MCSE 70 -293 Implementing Windows Cluster Services and Network Load Balancing Exam Objectives in this chapter: 4.1.1 Plan a high availability solution that uses clustering services 4.3 Implement a cluster server 4.3.1 Recover from cluster node failure 4.1.2 Plan a high availability solution that uses Network Load Balancing 4.4 Manage Network Load Balancing Tools might include the Network Load... the server will no longer boot.You replaced the failed hard drive with an identical one you had on hand.What is the quickest way to get the server back to its previous operational state? www.syngress.com 255 _70 _293_ch08.qxd 9/10/03 1:44 PM Page 635 Planning, Implementing, and Maintaining a High-Availability Strategy • Chapter 8 A Start an ASR restore Since the hard drive is new and identical to the failed... a server cluster is a group of independent servers that work together to increase application availability to client systems and appear to clients under one common name.The independent servers that make up a server cluster are individually called nodes Nodes in a server cluster monitor each other’s status through a communication mechanism called a heartbeat.The heartbeat is a series of messages that... select Safe Mode, and press Enter www.syngress.com 635 255 _70 _293_ch08.qxd 636 9/10/03 1:44 PM Page 636 Chapter 8 • Planning, Implementing, and Maintaining a High-Availability Strategy Planning for Fault Tolerance 13 You are responsible for administering a Windows Server 2003 system.The system has a Pentium III 800 MHz CPU, 1024MB of RAM, and four hard drives configured in a RAID 5 array that reside in an... implementing and managing NLB, including issues such as multiple network adapters, protocols and IP addressing, and NLB Manager logging Finally, we’ll address NLB security www.syngress.com 255 _70 _293_ch09.qxd 9/10/03 2:42 PM Page 641 Implementing Windows Cluster Services and Network Load Balancing • Chapter 9 EXAM 70 -293 OBJECTIVE 4.1.1 Making Server Clustering Part of Your High-Availability Plan Certain circumstances... Network Load Balancing • Chapter 9 Figure 9.9 Hot Standby/N+I Configuration, Failed State Failed State Public Network Active/ N Node Active/ N Node Virtual 2 Virtual 7 Virtual 3 Virtual 4 FAILED Node B Virtual 1 Virtual 6 Node A Passive/ I Node Virtual 5 FAILED Active/ N Node Node C Node D Failover Ring A failover ring is mainly used when all nodes in a server cluster are active.When a failover occurs, applications . is an essential part of a high-availability strategy.  Many things can cause loss of data—from hardware and software problems to human factors.  Good procedures are an indispensable part of a. Change the RAID array to a RAID 0 configuration. D. Increase the cache size on the array controller. www.syngress.com Planning, Implementing, and Maintaining a High-Availability Strategy • Chapter. contain? A: More than one CPU. Q: What are the three most common disk interfaces? A: ATA, SCSI, and Fibre Channel. Q: What happens when a data packet crosses a router from a network with a large