Module 1 / Planning Servers

Transcription

1 Planning Servers Module 1 / Planning Servers In this module, you will learn about server form factors and storage technologies. You will also learn how to plan and specify servers and document the server environment and how to install or deploy a Network Operating System (NOS). The following table lists the CompTIA Server+ domain objectives and content examples covered in the units in this module: Unit 1.1 Server Fundamentals 1.2 Configuration Management Domain Objectives / Examples 1.2 Deploy different chassis types and the appropriate components Form Factor [tower, rack, blade] (Space utilisation ([U size, height, width, depth]) Power buttons Reset buttons Diagnostic LEDs 2.4 Explain different server roles, their purpose and how they interact Explain the difference between a workstation, desktop and a server 4.1 Write, utilise and maintain documentation, diagrams and procedures Follow pre-installation plan when building or upgrading servers Labelling Diagram server racks and environment topologies Hardware and software upgrade, installation, configuration, server role and repair logs Document server baseline (before and after service) Original hardware configuration, service tags, asset management and warranty Vendor specific documentation (Reference proper manuals, Websites, Support channels [list of vendors]) 4.2 Given a scenario, explain the purpose of the following industry best practices Follow vendor specific server best practices (Documentation, Tools, Websites) Explore ramifications before implementing change determine organisational impact Communicate with stakeholders before taking action and upon completion of action Comply with all local laws / regulations, industry and corporate regulations Purpose of Service Level Agreement (SLAs) Follow change control procedures Equipment disposal 4.5 Given a scenario, classify physical security measures for a server location Secure documentation related to servers (Passwords, System configurations, Logs) Use the gtstrainer.com website to download resources to help to setup and run this course. If you don't have a login for gtstrainer or access to the Server+ course resources, sales@gtslearning.com. This module looks at the basic elements that need to be in place to install a server - chassis types, storage / RAID, and installing the NOS. Page 1

2 CompTIA Server+ Certification Support Skills (2009 Objectives) Unit 1.3 Storage and RAID 1.4 Installing an NOS Domain Objectives / Examples 1.3 Differentiate between memory features / types and given a scenario select appropriate memory RAID and hot spares 1.6 Given a scenario, install appropriate expansion cards into a server while taking fault tolerance into consideration Storage controller [SCSI, SATA, RAID] (SCSI low voltage / high voltage [LVD/HVD], SCSI IDs, Cables and connectors, Active vs. passive termination) 3.1 Describe RAID technologies and its features and benefits Hot spare Software vs. hardware Cache read/write levels (data loss potential) Performance benefits and tradeoffs 3.2 Given a scenario, select the appropriate RAID level 0, 1, 3, 5, 6, 10, 50 Performance benefits and tradeoffs 3.3 Install and configure different internal storage technologies Hot swappable vs. non-hot swappable SCSI, Ultra SCSI, Ultra320 (termination), LUNs SAS, SATA Flash Controller (firmware levels) Hard drive (firmware, JBOD) 6.5 Given a scenario, effectively troubleshoot storage problems, selecting the appropriate tools and methods Storage tools (RAID array management, Array management) 1.4 Explain the importance of a Hardware Compatibility List (HCL) Vendor standards for hardware Memory and processor compatibility Expansion cards compatibility 2.1 Install, deploy, configure and update NOS (Windows / *nix) Installation methods (optical media, USB, network share, PXE) o Imaging system cloning and deployment (Ghost, RIS/WDS, Altiris) Bootloader File systems (FAT, FAT32, NTFS, VMFS, ZFS, EXT3) Driver installation (Driver acquisition, Installation methods, Require media) Configure NOS (Device, OS environmental settings) Patch management 2.4 Explain different server roles, their purpose and how they interact Application server (Update server) Server shut down and start up sequence (one server vs. multiple servers vs. attached components) Page 2

3 Objectives On completion of this unit, you will be able to: Distinguish between servers and desktops and workstations and know what is meant by fault tolerance, availability, scalability, and load balancing. Identify basic server software functions and roles. Describe the features, advantages and disadvantages of tower, rack, and blade servers. Describe the features of rack-mounted equipment. Identify commonly-used rack-mounted peripherals and accessories. Delivery Tips Discuss the features that make server equipment different from desktop machines. Timings Theory & Review Questions - 45 minutes Identify the external features of a server case, such as the power button and diagnostic LEDs. Servers as Hardware and Software A server is any computer providing services to other computers, but usually the term server implies a powerful computer that supports a number of users simultaneously (in a computer network). The term "server" also means a software application that provides services to client applications. You will learn about examples of server applications later in the course. Servers and Desktops There is a distinction between server-class hardware and computers used as desktop PCs ("desktops") and workstations. A desktop PC is a low or medium spec machine provided to an end-user 1. 1 "Desktop" in this sense doesn't refer to the desktop form factor case. Most home and office computers come in tower cases but can still be referred to as desktops. Page 3

4 CompTIA Server+ Certification Support Skills (2009 Objectives) Any desktop PC can act as a server, but when a computer is designed to act as a server computer, it will have a number of features that distinguish it from a desktop computer. Some of the major manufacturers of PC servers include Hewlett- Packard (HP), Dell, Lenovo, IBM, Sun Microsystems, Fujitsu- Siemens, and Apple. High Availability and Fault Tolerance It is a well-known maxim that time costs money. Any time that an organisation's staff spend in the workplace without access to the computer system (downtime) is likely to be time wasted, and therefore a significant cost. If you calculate this cost based on the amount of time lost multiplied by employees' salaries, you can provide a cost-justification for upgrading the server equipment to improve reliability. Availability is not restricted to catastrophic crashes or complete system failures. A system that is slow is also costing time (and probably contributing to stress and low morale in the workplace). Availability is also critical when providing an interface for customers. If a web server crashes or responds slowly, it makes the company look inefficient at best; at worst it makes the company invisible (a customer can switch to a competitor's site with a couple of mouse clicks). Fault tolerance refers to a server's ability to keep serving even if something goes wrong. Availability is provided through the robustness of computer components and by providing for redundancy in the system (additional components that take over in the event of failure or extra capacity that can be utilised in high load conditions). Where redundancy is provided, the component is said to be n+1, where n is the number of components in use and 1 is a spare to be used in the event of failure. Another important feature is that as many configuration, maintenance, and repair operations as possible can take place without interrupting services (hot-swappable components for instance). Load Balancing Load balancing refers to distributing requests between multiple components. From the point-of-view of the client, there is only one resource. Page 4

5 In some configurations, having multiple components can provide load balancing and redundancy. If one of the components fails, the others can continue to provide the service, albeit at a reduced level of performance. Other load balancing configurations do not provide redundancy; if one component fails, the whole system goes down. Scalability Scalability means the ability to improve the performance of a server without diminishing its usefulness or increasing its cost disproportionately. A well-designed server is able to expand to meet the increased needs of its users. For example, if a company doubles its staff, it is likely to require about twice as much capacity from its server. If components such as an additional processor and more memory and disk drives can be added to the existing server then the server could be said to be scalable. The system is no more difficult to manage than before and performing the upgrade will have entailed a minimum of downtime. Contrast this with the circumstance in which a company had to buy a new server or an additional server. These solutions cannot be said to be scalable as they involve greater expense and complexity of administration. Workstations A workstation is a high-spec machine provided to "power users", such as designers or developers. A workstation may have some of the features associated with servers, such as multiple processors and redundant disks (RAID). A workstation may also be able to function quite competently as a server in a small workgroup (up to about 10 users) 2. At the entry-level, server computers are not that much more expensive than desktops. Most businesses would require enterprise-class features however and these quickly increase the required budget. 2 Workstations can also be provided through server-like infrastructure. For example, HP produce blade workstations accessed remotely via client PCs. The main difference between such a workstation and a server is that the workstation is likely to have a highperformance graphics adapter. Servers only require basic graphics functionality while workstations used in the design industry need to be able to do 3D and texture processing. Page 5

6 CompTIA Server+ Certification Support Skills (2009 Objectives) Server Roles While "server" can refer to the computer hardware, the term also refers to software. This can broadly be divided into Network Operating System server platform and server applications software. Server Platform The server platform is the underlying Network Operating System (NOS). This will usually be a version of Windows Server or some "flavour" of Linux. The server platform is likely to include a number of basic roles enabling the server to provide local and remote user authentication, network services (routing, DHCP, and DNS), file and printer sharing, and web, FTP, and . The current trend is for virtualised server platforms. This means that a single hardware server, installed with a virtual machine manager or hypervisor, hosts multiple OS platforms. These multiple instances or VMs could all be running similar services (web servers for instance) or different types of application. Web Hosting Running web services is one of the most common server roles. As mentioned above, any server platform can host a basic website but web services are very often provisioned on a larger scale. Windows Server Internet Information Services web server Page 6

7 Internet Service Providers (ISPs) operate huge web server farms to provide web hosting services to subscribers. Enterprise websites are also backed up by multiple servers for load balancing and availability. Messaging, Groupware, and Collaboration Messaging servers provide services such as , Voice over IP (VoIP), Instant Messaging (IM), and web conferencing. The same machines may also run "groupware" services, allowing users to arrange meetings and collaborate on projects and documents. Media / Streaming Servers designed to serve audio and video files to large numbers of users are often provisioned as dedicated hardware, separated from the web server(s) to improve performance and availability. Application, Database, and Middleware A client-server application can be designed for any sort of business function (Customer Relationship Management [CRM] and accounting are typical examples). These applications often feature split front- and back-end servers. The front-end servers host the user interface while the back-end servers host the database. There may also be "middle" tiers supporting functions such as business logic and data queries. Small Business Enterprise networks run multiple server applications on multiple server machines, physical and virtual. Small and Medium Size Enterprises (SME) may use "one-box" solutions, such as Microsoft's Small Business Server. As well as the underlying OS platform, the server provides messaging and calendaring (Exchange), collaboration (SharePoint), database (SQL Server), and (in some editions) a firewall and proxy server (Internet Security and Acceleration [ISA] Server). Page 7

8 CompTIA Server+ Certification Support Skills (2009 Objectives) Server Form Factors A server's form factor is the type of case it uses. Tower Servers If you have web access, you may want to visit some vendor websites (HP, Dell, Sun, IBM, and so on) to view some systems on sale. Note that these sites are also valuable information resources, with white papers and assistance often easily accessible. A tower server uses the same sort of case as a PC. Often the case is substantially larger and the design gives more thought to providing airflow through the case, improving cooling. This allows flexibility in terms of placement and is the cheapest option. Tower servers are available in a wide range of models, allowing for different budgets and requirements. They are also usually the easiest machines to customise and upgrade. HP full tower server A tower server is a good option if only a few servers need to be stored. However, when the server equipment needs to be integrated with network equipment or where an organisation needs to be able to grow processing power rapidly and effectively, a rackmounted solution is required. Rack-mounted Servers Rack servers are designed to bolt into racks. They are built to fit within a standard width (19" / 48.26cm) and height. The height of the case will be a multiple of 1.75" / 4.45cm called a U. They look somewhat similar to the old desktop form factor PCs, but are not designed to be placed free-standing on a desk. HP Proliant 4U (left) and 1U (right) rack-mounted servers Rack servers can be far more compact than tower servers, but contain the same components. Notably, each server has its own cooling solution. Page 8

9 The cost of buying rack equipment makes rack-mounted servers seem a more expensive option than tower servers, but these costs can be offset by the greater security and manageability of rackmounted equipment. Rack-mounted equipment also allows the server array to grow more easily. Racks are said to offer density, as units can be stacked vertically as well as horizontally. Blade Servers A blade server is a space-saving variation of a rack server. The power and cooling systems are not incorporated within the server unit. Instead, servers are housed in very thin cases installed together in an enclosure like books in a book case. Each enclosure shares a common power and cooling system and also I/O and network ports. HP Proliant blade server (front view) and enclosure (back view) Each machine is typically identically configured in terms of number and type of processors, system memory, and disk drive provision. Blade servers offer the best density of any server form factor. A rack that can fit 42 1U servers could fit 60 blade servers. The individual server units are usually fairly low cost (though not as cheap as similarly specified 1U rack servers), allowing the organisation to grow capacity organically. An extra consideration is the overall power consumption of the rack, especially as energy prices are likely to continue to rise. With shared power and cooling, blade servers are typically more efficient than ordinary rack-mounted servers. Also, cable management is significantly easier. As a relatively new technology, one problem with blade servers is the lack of standards. Machines from different manufacturers (IBM, HP, and Dell) cannot be integrated in the same chassis. Page 9