Linux操作系統(tǒng)01-簡介

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1、單擊此處編輯母版標題樣式,單擊此處編輯母版文本樣式,第二級,第三級,第四級,第五級,Acegene IT Co.Ltd.,*,Linux,操作系統(tǒng),簡介,Linux之家,,1,Acegene IT Co.Ltd.,內(nèi)容提要,Linux,簡介,Linux,的安裝,SHELL,及常用程序,文件編輯器,vi,目錄和文件管理,文件系統(tǒng)管理,用戶管理,網(wǎng)絡(luò)管理,網(wǎng)絡(luò)文件系統(tǒng),模塊安裝和配置,系統(tǒng)管理,系統(tǒng)優(yōu)化,開發(fā)工具,Internet,管理,2,Acegene IT Co.Ltd.,Linux,簡介,Linux,操作系統(tǒng)是可以運行在許多不同類型的計算機上的一種操作系統(tǒng)的“內(nèi)核”。它是提供命令行或者程序

2、與計算機硬件之間接口的軟件的核心部分。,Linux,操作系統(tǒng)內(nèi)核管理以下事情：比如內(nèi)存、采用什么方法以及在什么時候打開或者關(guān)閉文件、哪一個進程或者程序可以獲得計算機的中央處理單元,(CPU),等等。,Linux,操作系統(tǒng)可以說是,UNIX,操作系統(tǒng)的一個克隆體，它最初是在,1991,年,10,月,5,日由它的作者,Linus,Torvalds,于赫爾辛基大學發(fā)布的。,3,Acegene IT Co.Ltd.,Linux,功能,所有主要的網(wǎng)絡(luò)協(xié)議,硬盤配額支持,全部的源代碼,國際化的字體和鍵盤,作業(yè)控制,數(shù)學協(xié)處理器仿真,內(nèi)存保護,多平臺,多處理器,多用戶,多任務(wù),共享的庫文件,支持多種文件系統(tǒng)

3、,虛擬控制臺,虛擬內(nèi)存,其他更多功能,4,Acegene IT Co.Ltd.,GPL,和,Free,Linux,操作系統(tǒng)遵從,GNU,公共許可證（,GNU Public License,，簡稱,GPL,）的規(guī)定。,Linux,對外的一個重要的特點就是,”,Free”,，自由和免費。,5,Acegene IT Co.Ltd.,What is Linux?,Linux is an operating system with the following attributes:,Multi-user,Multi-tasking,Virtual memory system,X-Windows,Comp

4、atible with the IEEE POSIX.1 standard,Non-proprietary source code,Source code is available,6,Acegene IT Co.Ltd.,Is Linux the same as UNIX?,The command set is similar,They work the same,They look the same,Linux cannot use the UNIX trademark,Linux is essentially UNIX,7,Acegene IT Co.Ltd.,Is Linux a re

5、al OS?,Yes,absolutely,Linux is used,In mission critical applications,Around the world,There are many flavors of Linux available,We call them:Distributions,8,Acegene IT Co.Ltd.,Linux,發(fā)行版本的概念,大多數(shù)的,Linux,操作系統(tǒng)的發(fā)行版本都使用標準的,Linux,內(nèi)核，但有時候也會稍微加以修改，這個操作系統(tǒng)現(xiàn)在的規(guī)模已經(jīng)變得相當龐大了，因此許多人更愿意購買一張它的,CD-ROM,光盤。每一種發(fā)行版本彼此之間都稍微有

6、一些差異，這些差異主要表現(xiàn)在它們各自的安裝程序包上，還表現(xiàn)在安全性與可用性等方面?zhèn)戎攸c的不同。把系統(tǒng)內(nèi)核、附帶的工具程序及應(yīng)用軟件包等等打包在一起，這樣組成的一個,Linux,操作系統(tǒng)的集合體就是我們說的某一種發(fā)行版本。,9,Acegene IT Co.Ltd.,誰使用,Linux,操作系統(tǒng),Linux,正在逐漸贏得普通用戶的青睞。但是它仍然不是一個適用于普通大眾的操作系統(tǒng)。對那些習慣了當今鼠標界面操作系統(tǒng)的人們來說，學習仍是很困難的。需要學習一大套從未接觸過的命令，還需要學習與長期形成的概念不相同的那些對待與處理事情的方法。對那些具有,UNIX,操作系統(tǒng)使用經(jīng)驗的人們來說，,Linux,可是

7、容易多了。,專業(yè)用戶、系統(tǒng)管理員和計算機開發(fā)人員通常都會比一般的用戶更容易掌握,Linux,操作系統(tǒng)。但就是對這些人來說，這方面的學習與實踐也需要有足夠的耐心與專心。,10,Acegene IT Co.Ltd.,Enterprise vs.Retail,Retail distributions,Faster release cycles(4-6 months),Geared for home/productivity users,Shorter support lifetimes,Examples:RHL9,SuSE,Linux 9,Enterprise level distributions

8、,Slower release cycles(12-18 months),Longer support lifetimes(3-5 years),Examples:RHEL3/4,SLES9,Adds performance and scalability enhancements,11,Acegene IT Co.Ltd.,Linux Distribution Overview,The core parts of a Linux system are:,Linux kernel,User space utilities and applications,The kernel and user

9、 space programs together make up the complete operating system,Linux Kernel,Core component of the operating system,Configurable and tunable,Provides main OS functions,I/O,disk,network,etc.,CPU Scheduling,Memory management,uname,-r shows the kernel version number:,#uname-r,2.4.9-e.25,Kernel concepts,

10、Linux is based on a modular non-microkernel architecture,All device drivers share the same memory with the kernel,Device drivers are modular and can be loaded/unloaded dynamically,Linux is multi-tasking,Linux is a virtual-memory OS,Most kernel parameters can be modified on the fly,14,Acegene IT Co.L

11、td.,All components of the operating system are delivered via RPM packages,Kernel,System utilities,Applications,Both Red Hat and SLES8 distributions use the RPM Package Manager(RPM),Originally named“Red Hat Package Manager”,Software Packages,Linux Updates,Apply the recommended updates by the distribu

12、tion vendor:,Most vendors provide automatic updates,Red Hat Network supplies updates automatically,up2date,SuSE uses,YaST2,(Yet Another Setup Tool 2),you,(,YaST,Online Update),Linux Enterprise Features,Linux enterprise features support:,Performance,Scalability,Reliability,Symmetric Multiprocessing,F

13、ully multiprocessor capable(SMP),RHEL3:16 processors,SLES8:32 processors,Uniprocessor,configuration supported on both,Intel,Hyperthreading,(HT)enabled on IA-32,Physical-to-logical CPU affinity scheduling,18,Acegene IT Co.Ltd.,Improved Memory Utilization,Use more than 4GB of RAM on IA-32,RHEL 2.1:max

14、 16GB supported,RHEL3:max 64GB supported,SLES8:up to 64GB supported,Some older drivers not capable of accessing more than 4GB of RAM,May perform“bounce buffering”to compensate,Usually not a concern for enterprise-class drivers,Kernel memory used more efficiently than before,Run more processes withou

15、t swapping,19,Acegene IT Co.Ltd.,Virtual Memory,Each process has a private address space,Keeps private data in memory secure,Prevents inter-process data corruption,Contiguous view of memory,Demand-based paging,Pages are“swapped”out when low on RAM,Pages are“swapped”in when accessed again,Allows the

16、system to use more memory than any single space can address,20,Acegene IT Co.Ltd.,Virtual,Filesystem,(VFS),Linux supports multiple file systems,OS is file system independent,Multiple file systems can be used simultaneously,Cross-platform compatibility,Performance,VFS provides a single,filesystem,interface,Filesystems,Important ones to know:,ext2/3 -Red Hat default(ext3),reiserfs,-SLES8 default,NFS -Network,Filesystem,Procfs,-kernel virtual,filesystem,ISO 9660(CD-ROM),OCFS -Oracle Cluster,Filesys