Linux system administration, second edition: Phần 2

(BQ) Part 1 of the is serial Tài liệu Pc Underground to part 2 of you will continue to learn about relevant issues such as: Creating and maintaining user accounts, disk management, filesystems management, linux files and processes, software administration, backup and Restore,... Invite you to consult the lecture to learn more about this content.
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Linux system administration, second edition: Phần 2Part III: Communications and NetworkingChapter ListChapter 10: Printers and the Spooling SubsystemChapter 11: Serial Communications, Terminals, and ModemsChapter 12: TCP/IP Linux NetworkingChapter 13: The X Window SystemChapter 14: Setting Up Your Mail ServerFeaturing • Understanding serial devices • Configuring terminals and modems • Configuring serial printers • The printing process in Linux and the lpd print spooler • Creating printers in Red Hat • Kernel support for printing • Remote printing • Bash shell scripting • Administrative scripting in other languages • Understanding and configuring TCP/IP networking • File sharing • Internet servers and super servers • Configuring the X Window System • Building a user interface atop X • Setting up a mail server • Protecting against spam 246Chapter 10: Printers and the Spooling SubsystemOverviewPrinters are critical tools for most businesses, and that makes the ability to set up and administerprinting a very important system administration task. You will find that many of the emergency callsyou receive are from users who cannot print a document they need for an upcoming meeting. Evenwhen something small goes wrong with a printer, it seems like a crisis to anyone who needs thatprinter at that specific time. A successful system administrator must understand the printing processand be able to successfully troubleshoot basic printing problems.Printing under Linux works somewhat differently than does printing under most non−Unix operatingsystems. If all works well, these differences are transparent to your users, but you must understandmany of Linuxs printing details and peculiarities in order to set up and troubleshoot a Linux printingqueue. You must also understand how these queues interact with clients if the computer functionsas a print server for other computers. This chapter outlines the types of printers commonly usedtoday, the tools Linux provides for controlling printer operation, and basic installation andconfiguration.Printer BasicsPrinters are classified both by the way they print and the way they connect to the computer. Thereare three main types of printers and four types of printer interfaces you may encounter. Familiaritywith these printer basics makes you a more capable system administrator and helps your users totrust that you know what youre doing. A brief introduction to types of printers and the ways theyinterface with the computer will be helpful. If you already know these basics, you can skip ahead toThe Printing Process in Linux.Types of PrintersPrinters differ radically in the way they create images on paper. Impact printers mechanically strikecharacters against inked ribbons to transfer an image to paper. These have limited and specializeduses in todays business world; more common are nonimpact printers, which transfer images byother means. Impact printers include line printers, daisy−wheel printers, and dot−matrix printers.Nonimpact printers include laser printers and ink−jet printers. Some of the earliest common printersfor mainframe computers were line printers—big, fast, and noisy. Daisy−wheel printers wereintroduced in 1970, offering the same print quality as typewriters. Soon after, the dot−matrix printereffectively replaced the daisy−wheel. Laser printers hit the scene in 1975 but the cost wasprohibitive, so most businesses continued to use dot−matrix printers. In 1976 when the first ink−jetcame out, it too was cost−prohibitive. In 1988, Hewlett−Packard released the DeskJet ink−jetprinter, which was priced at $1,000. Although many users kept their dot−matrix printers instead ofpaying for the better capability, this series of printers opened the door to widespread use of ink−jetsby home users. Laser printers were still far too expensive and didnt do color like the ink−jets. In1992, Hewlett−Packard introduced the LaserJet 4, which supported resolutions up to 600×600.Color laser printers were introduced in 1994. The market now is pretty much shared between ink−jetand laser printers. There are, however, a few printer types that are important in niche markets, suchas dye sublimation and thermal wax transfer printers, which are popular in graphic artsdepartments. 247Dot−Matrix PrintersDot−matrix impact printers have a number of pins (usually between 9 and 24) arranged in a verticalline. The printer shoots some of them into an inked printer ribbon, leaving a number of dots on thepaper, which produces a fuzzy, low−quality representation of the intended letter. The fuzziness isdue to the mechanical nature of the pins; they simply cannot be made small enough to hide the factthat the letters are made up of dot ...