Question 1: What are some reasons an organization might choose one operating system over another?

Transcription

1 Question 1: What are some reasons an organization might choose one operating system over another? Answer 1: An organization chooses a network operating system (NOS) for several possible reasons. The system chosen must meet the need of the organization and the ability of the users. Administration Most administrators prefer the control of a script capable NOS. They would like to be able to direct the management function with a command-line interface, which can be more specific than the general administration application. The use of command line can specifically be directed to a device (printer #1), user group (guest group, admin group), applications set (MS Office), or text files (myusers.txt) whether it is encrypted or not. If it is encrypted, the requestor will also be provided the key if he/she is authorized to use the file. The keyrelease process is role specific. Internally the OS maintains a permission database that provides access control to the file system; the role of the user may not have permission to access system files whereas the administrator role would. Use of the command-line interface also requires knowledge of command programming and scripting that most users do not understand. Specificity of the command line provides better control of the system. Common Users Having addressed the issue of administrators and their preference, normal users (those having no need of the command interface) would prefer an operating system that does not require programming skills. Most think that having to type a list of specifically formatted phrases in command line is too tedious and time consuming when all they really need to do is use the pointing devices and click. Most users have no understanding of proper programming so ease of use is a defining criterion for selection (Dean, 2006). Training Would the users require more training to use the new system? Would the administration staff need training (Dean, 2006)? Cost 1

2 Cost is always an issue. Why pay that much money for a system when something like it is cheaper (Dean, 2006)? System Support Can the organization support the systems with its technicians or will the support have to be outsourced (Dean, 2006)? Looking to the Future Is there something that will be available in the near term that would be better than the current possible operating systems? Will the system have to be upgraded again soon? Choices If the new system meets all the needs of the organization, then that is the system to choose; more often though, trade-offs (compromises) are required (Dean, 2006). Question 2: What is the Hardware Compatibility List, and how does it influence NOS selection? Answer 2: The HCL (Hardware Compatibility List) is a list of devices that have been tested to work on various operating systems. Not all hardware will work with all operating systems. Most devices that have been tested have drivers that either are built into the OS or require mounting. Windows assigns a system location for the devices and a file location for their corresponding drivers (software that allows the OS to communicate with the device) and has incorporated a few into the OS. UNIX drivers require mounting. Linux and Novell are similar to UNIX. Drivers are developed for the devices being used in an operating environment (platform designated by it OS), or some may be supported by a generic driver. Then, generic drivers will connect the devices and provide minimal operating ability until the specific one can be downloaded (if available). The manufacturer of a device must provide the driver (Dean, 2006). Checking with the maker will help to decide which devices will work in one's OS environment. Most organizations have a variety of hardware used in their enterprise, such as routers, printers, scanners, plotters, hubs, switches, and telephone interfaces. Some basic computer systems may not work with some operating systems because they do not have the minimum system specification for 2

3 implementation (designated by the OS). The organization must choose a NOS that provides best compatibility for most of its hardware. The HCL will provide the whole list of current devices the OS supports. If you cannot use the device, there is no reason to include it in one's network. Refer to your Web resources for the primary network operating system Web sites for HCL. Question 3: What are the minimum hardware (computer and peripherals) requirements for the following OSs listed? Answer 3: The following are the minimum hardware requirements for the following OSs (Dean, 2006): Windows Server 2003 Solaris10 MAC OS X Processor MHz or higher Pentium type (550 MHz) is recommended. The install supports four processors in a single server. Memory MB of RAM is the absolute minimum (recommended 256 MB) maximum supported is of 4 GB of RAM. Storage - Compatible hard drive with 1.5 GB of free space just for the system file CD/ROM is required unless the install is over a network connection. The 2003 version is able to use multiple NICs. A pointing device (mouse optic pen) is required. Processor - AMD or Pentium Memory MB of RAM Storage 5 to 7 GB CD /ROM or DVD/ROM drive for input Solaris 10 can support up to 128 processors per server (clustering is possible). Processor - G3, G4, G5, imac, emac (Macintosh computers), or an Intel Pentium 3 (as of Aug. 2005) platform Memory MB of RAM Storage - 4 GB of available disk space 3

4 Linux Server CD/DVD drive required Processor - Intel X86 compatible (any AMD/Intel) Memory - 64 MB of RAM Storage - Linux compatible hard disk drive with 2 GB of free space Linux compatible CD/ROM drive or paired 3.5 inch floppy disk Novell Netware 6.5 Server Processor - IBM compatible Pentium II AMD K7 - Up to 32 processors can be supported at one time. Memory MB of RAM (recommended 1 GB) Storage - at least 2 GB of free space (recommended 4GB) CD/ROM required for install Question 4: What applications must be installed on a Windows server to connect to a NetWare 6.5 network segment to share resources? Answer 4: Windows and Novell Netware are both TCP/IP protocol-based operating systems, so many users would think that all they would have to do is connect. That is not the case. The file systems supported by Windows are NTFS (New Technology File System), FAT 32 (32-bit file allocation table), and FAT 16 (16- bit file allocation table). The file system primarily supported by NetWare is NSS, Novell Storage Services. Older file systems can be run, but they require an additional optional application, Taditional File System. It has limitations allowing read only permissions. Windows and Novell must have special applications installed to permit the sharing network resources. Those applications are additional services included in the operating system file set and, depending on the NOS installed, will add between 1.2 GB to 2.5 GB to the required minimum hard drive space (Davis & Rajkumar, 2004). Clients on a NetWare server (V5 or V6) requiring to view and access resources on a Windows server system must have client services for NetWare installed on the Windows server (Dean, 2006). After that installation, the Window shared drive and file set will be able to be seen by the Novell clients similarly as any other shared resource sever (listed like a print server, i.e., name.prtn). 4

5 How would one access the Windows Server 2003 Active Directory with updated information about the user accounts in the NetWare clients' files (Dean, 2006)? That too is a special application (part of the suite of applications found in the Microsoft Windows Services for NetWare available with the Windows NOS). Installation of Microsoft Directory Synchronization Service (MSDSS) provides administrative access between Windows Active Directory and NetWare's edirectory database (Dean, 2006). The Windows server must be the domain controller to run this service. Perhaps a Windows client on a Windows server needs access to the NetWare server. A Windows client can access the Netware server if the Windows server has installed Client Services for NetWare (CSNW) and NWLink. These two services permit a Windows client to log on to a NetWare server to access services like printers, files, and other resources controlled by that server. Interoperability is important in a multiplatform environment ensuring that the services needed by the organization are met. Question 5: Windows and UNIX-based network operating systems can work together; what is needed to support that interoperability? Answer 5: Unix-based network operating system servers all work similarly (grouping UNIX and Linux together), but they have certain applications that are needed to work with Windows servers that provide interoperability. If LDAP (Lightweight Directory Access Protocols) are not established on both systems' servers, then NOS intercommunication cannot be implemented. Another application-based interface is Samba. Samba is a client/server application that allows UNIX systems to communicate with Windows Servers. What allows Windows to communicate with UNIX? This is a little more complex. LDAP lets both UNIXtype systems and Windows have common access to a service. It sets up a common directory format, and because it is TCP/IP and the LDAP compatible, it establishes the standard data that can be shared. What happens if the LDAP is not established between Windows and UNIX? Windows can fix that too (Dean, 2006). Microsoft has software that comes with the server OS that will integrate the servers' directory allowing the clients on the UNIX side to access resources to the Windows resources. That application belongs to the Microsoft Service for UNIX suite. This may be surprising but one of the latest versions of a UNIX-based OS today is MAC OS X. OS X is based on an open source UNIX kernel called BSD (Berkley Software Distribution). MAC OS X Server is a proprietary UNIX OS (Dean, 2006). The interface between MAC and Windows is the same as for UNIX. As a side bar, the latest versions of Novell NetWare have incorporated a SUSE Linux kernel into its OS making it usable 5

6 with the UNIX interface too. Question 6: What are some of the specified services needed by clients in a client/server NOS environment? Answer 6: The requirements for client support vary based on organizational needs. Generally, the NOS provides the client with access to its resources and files. Not all files are accessible. It provides connection between clients on the LAN, external access to the Web-based application, and distributed file access (files located within the organizational network--intranet and Extranet). Access to network printers and databases are granted by the administrator as part of the user's access definition. Establishing access permission files for all local users and universal user groups provides a single location within the organization identifying who has access to which resources. It also establishes what type of access a users has: administrator, power user, normal user, or guest. The administrator has full control to read, write, execute, modify, and access all files in the system. This should be kept to an absolute minimum. Power users have some minor administration function or authority like creating a limited access user account or initiating the system backup. The users have no administrative privilege. They are only allowed to access specified files and applications needed to complete the organizational work responsibility. All access to critical organizational data is minimized. This concept supports the security objective of providing access only to things that are needed for completion of one's responsibility and nothing else--permission based on least privilege. Guest access is granted temporarily for a specific purpose, like a system upgrade or software installation from outside the organization. It is fully monitored. It is time limited and minimal access password supported. Once the purpose has been accomplished, access and password is revoked. Each role aforementioned specifies services available to that level. Additionally, internal shares (peer-to-peer) between users are maintained by the system, the password, certificate storage, and key management for the local network (Dean, 2006). Client services permit the user to do his/her job. 6

7 Question 7: What is the benefit of having centralized/decentralized servers in a network? Answer 7: Centralized networks, laid out in a LAN (local area network), usually have a central server room to manage the day-to-day activities of the organization's network. A centralized server system is sometimes called a server farm (Palmer, 2006). The central location provides easy access to the devices, wiring, support servers, and a single point to update the network. Attempting changes to the components of the network can be quickly detected and prevented if necessary. The server room provides a physical security system to the network management components and support software. A centralized server configuration saves money by consolidating the organizational requirements for servers into a location providing unique environmental control (air-conditioning, ventilation), power grid services, backup services, and it can be supported by UPS (uninterruptible power supplies) systems (Palmer, 2006). A disadvantage is that a disaster, natural or otherwise, can damage all the organizational servers at one time. This is a single point of failure (Palmer, 2006). Decentralized networks, laid out in most medium and large businesses, have multiple sites, and each site may have a different focus, such as billing, insurance, personnel, and so forth. The decentralized or distributed server system can provide the organizational services from more than one location. System backups can be sent across the network (WAN--extranet). Services do not need to be localized. Generally, the servers are managed locally by an administrator and customized to support the local mission. The personal records might be in New York while the pay records are in San Francisco. The marketing data files can be at one place and research and development can be at another. Across several locations, backup servers can store and update data, then redistribute the undated information elsewhere preventing the single point of failure. Disasters will have little effect on the distributed system (Palmer, 2006). One of the biggest disadvantages with a decentralized system is the security implemented across the network. Some places may provide better security than others may. Additionally, maintaining access control internally from site-to-site and keeping the user accounts updated could stress the system (Palmer, 2006). Question 8: Which operating system provides the most flexibility in developing services? 7

8 Answer 8: While Windows and Novell servers have canned functionality, all standard management processes and services are built into the OS. The systems are proprietary and cannot be modified to compensate for full integration of non- HCL listed components. Even though Windows provides generic drivers that permit temporary use of some devices, the efficiency of the device will never reach full capability if the device does not have a Windows-compatible driver. Likewise, Novell NetWare requires a proprietary NetWare driver for full functionality. That leaves UNIX and Linux operating systems to fill the gap. Linux and UNIX operating systems are still written in C and C++, which are both an object-oriented programming language, and the Linux kernel is open source and usable on all UNIX-like environments. As we have mentioned before, the UNIX-based OS can be used or integrated for interoperability with all other NOS (Rowe & Schuh, 2005). Therefore, applications and software written for a UNIX system can be incorporated for use with other NOS. Drivers are software that allows the OS to talk to the devices; therefore, writing a Linux/UNIX driver for a device can be utilized by the proprietary NOS with the supported interface installation. In fact, nearly 70% of all Web-based services in the world are supported by a UNIX-based operating system, primarily a Linux derivation, and the number is growing (Rowe & Schuh, 2005). UNIX-based programs can be accessed as well, making the UNIX-based NOS the most flexible. If it is so flexible, why have any other OS? Most organization's network focus is on the usability of the worker not designing the structure or software for the network. They leave that to experts. Programming is not a normal requirement for users. The following operating systems provide all the applications normally used in business: Microsoft provides MS-Office, and IBM Solutions supports WordPerfect, DB4, and even some UNIX. SOLARIS 10 commonly has a database, word processing, and presentation application. Specific applications like mysql, SQL server (pronounced Sea quail server-sql stands for structured query language), Oracle, and the like incorporate with data structure supported by the business application. Basically, there are users, workers, clients, programmers, and administrators in networking. Both programmers and administrators prefer the specificity of the UNIX environment while the rest would rather just do their job and use the services provided. Without a doubt, the ability to program and incorporate system specific applications with UNIX-like OSs make it the candidate of choice for flexibility (Rowe & Schuh, 2005). 8

9 Question 9: What are some differences between Windows Server 2003 and the following Linux servers? Answer 9: Windows Server 2003 has several versions of the operating system, depending on the organizational need. Each is specifically designed as a primary NOS with additional built-in support applications. The Standard Edition provides basic resource sharing and management commonly used for small to medium businesses. It can establish a symmetrical-multiprocessing environment for up to four processors in each server. Symmetrical multiprocessing refers to the balanced use of processing time for all tasks (Dean, 2006). The Web Edition is specifically designed to support Web hosting and services including XML, HTTP, HTML scripting applications, and Web site development. The Web Edition is intended for easily deployed and managed Web serving and hosting (Rowe & Schuh, 2005). The Enterprise Edition supports up to eight processors on each server and come in two memory formats able to manage both 32 GB RAM in a 32-bit version or 64 GB RAM in a 64-bit version--more memory gives more reliability. It supports server clustering (multiple processors seen and act as a single computer) and promotes a high level of reliability (Dean, 2006). Datacenter Edition provides support for up to 32 processors per server in a 32-bit format and 64 processors in a 64-bit format, providing support for up to 64 GB of RAM in a 32-bit version and 512 GB RAM using the 64-bit version. This version is designed to provide the highest level of reliability and performance of all Windows versions. Windows Server 2003 and Mac OSX are the only NOSs currently supporting the 64-bit versions. The higher the bit rating, the faster the processing takes place (Dean, 2006). The other NOS is based on a single install for unique configuration.windows Server 2003 does not support NetBEUI protocols that are commonly used in the TCP/IP- based networks to transfer network messaging inside the network. This protocol is a nonroutable, low efficient format; however, it is used by all other TCP/IP NOS (Dean, 2006). Windows Server 2003 provides full integration with IPv6 support for Point-to- Point Protocol over Ethernet (PPPoE) and Internet Protocol Security (IPSec) over NAT (Internet Protocol security (encryption) overt network address 9

10 translation) services. These processes are also incorporated into Microsoft.NET Web-based services making integration with operating systems over the Web plausible. An administrator can control most tasks with the command console or with a series of automated tools. Management applications are predefined using Microsoft Management Console (MMC). The routines or snap-ins provide tools for common tasks like creating accounts, changing passwords, monitoring event logs by the system administrator, and permitting the administrators to script their own snap-in and service calls. Service snap-ins minimize the need for command-line interfaces (Dean, 2006). Although Linux has some of the administrator services available through the GUI (iconic interface), the majority of the administrative activities must still be through the command-line interface. Nearly all the administration processes in Windows Server 2003 can be executed by snap-in. Microsoft Windows Server 2003 maintains its files and management system using an application called Active Directory (AD) (Davis & Rajkumar, 2004). Active Directory works as the system manager and domain controllers (primary and backup domain controllers (PDC, BDC). In other operating systems, the system manager must be delegated to servers and configured to support server management. No automatic assignment is available. The exception is that in Novell Netware 6.5, NDS (Netware Directory Service), and e-directory assume the role as domain control. The purpose of Active Directory is to provide system copies of the user account data and store snapshots of the system for recovery requirements so that in the event a server fails, the system will automatically have access to user accounts on the other server and provide for immediate roll-back recovery. Any server that AD is installed on will have the user data (Dean, 2006). This may be a problem for security if all user data, including password files, are stored in several places; the loss of data is more of a system vulnerability. In Windows Server 2003, file management supports the following file types: FAT16, FAT32, UDF (Universal Disk Format used on CD-ROMs), CDFS (CD-ROM File System allowing CD file sharing and application installation), and NTFS (New Technology File System). However, the common FAT16 and FAT32 are supported by other OSs (Novell). The UDF support is available on Linux and Novell platforms not UNIX or MAC OS X. UNIX/Linux NFS cannot directly be supported by Window Server 2003 (Windows Server 2003) but can be managed with SAMBA. NTFS is the file system of choice with Windows Server 2003 and XP because of its security support (Davis & Rajkumar, 2004). Files managed in NTFS can be stored as encrypted files and transferred from one NTFS system to another; however, the 10

11 encryption remains enforced. When transferring to a different file system, the encryptions are received in plain text. NTFS is supported by the security suite Kerberos, which establishes security mechanisms and authentication controls for the network. Kerberos is available with other OSs but as an option not a standard. NTFS supports Windows Server 2003 processor 64-bit format. It can establish file partition as large as 16 Exabytes (264 bytes, which is huge). No other NOS can make that claim. For Windows Server 2003 to communicate with MAC OS X, NTFS must be used (Dean, 2006). Finally, built into NTFS is a compression algorithm that can automatically compress files up to 40%, saving disk space (10 GB HD full converted to NTFS will use only 6 GB). None of the other NOSs have that ratio of compression. Windows Server 2003 was designed to provide a wholly GUI interface for all activities, providing ease of use and a very short learning curve. Just turn it on, logon, and go. It uses a familiar interface, mouse base execution (pointer pen also), and stored system applications. UNIX and some Linux distributions rely on the command-line interface. Though a GUI interface is available for both, the applications to support the OS are still mostly command lines scripts. Both Mac OS X and Netware provide primary GUI interfaces, again the built-in applications are limited, and third party support is needed (Dean, 2006). Question 10: Networks with more than one NOS have difficulty with simple file sharing services. What provides file sharing between platforms? Answer 10: The file access protocols provide different OSs access to different file formats (Dean, 2006). Within Windows Server 2003 and Windows XP, file access is through CIFS (Common Internet Files System) (Davis & Rajkumar, 2004). CIFS is already widely supported in commercial software products such as AT&T, Advanced Server for UNIX (ASU), IBM Warp Connect, IBM LAN Server, and Novell Enterprise Toolkit. CIFS is the featured file and print sharing protocol of SAMBA, available for Linux and many UNIX platforms. This protocol replaced the older version of client/ server protocol called SMB (Server Message Block) used with IBM and UNIX type OS and later with Windows 9X and NT (Dean, 2006). Additionally, connecting network platforms requires unique applications to support the data transfer and system share. Novell Client for Windows (all versions) provides Window Server control of Novell client nodes. SAMBA allows sharing of files in both client and server configurations by a UNIX/Linux 11

12 platform supporting Window and Mac OS X (Davis & Rajkumar, 2004). In some cases, a universal "software application called middleware is necessary to translate request and response between the client and server" (Dean, 2006). With middleware, the aforementioned interface applications are unnecessary. Middleware can support multiplatform networks with no additional application install. References Davis, W. S., & Rajkumar, T. M. (2004). Operating systems: A systematic view (6th ed.). Boston: Addison-Wesley. Dean, T. (2006). Network+ guide to networks (4th ed.). Boston: Thomson. Palmer, M. (2006). Hands-on networking fundamentals. Boston: Thomson. Rowe, S. H., & Schuh, M. L. (2005). Computer networking. Upper Saddle River, NJ: Prentice Hall. 12