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Acegene IT Co. Ltd. 1
Linux操作系统
简介
周炯
上海艾基信息技术有限公司
Acegene IT Co. Ltd. 2
内容提要
• Linux简介
• Linux的安装
• SHELL及常用程序
• 文件编辑器vi
• 目录和文件管理
• 文件系统管理
• 用户管理
• 网络管理
• 网络文件系统
• 模块安装和配置...
Acegene IT Co. Ltd. 3
Linux——简介
• Linux操作系统是可以运行在许多不同类型的计
算机上的一种操作系统的“内核”。它是提供命
令行或者程序与计算机硬件之间接口的软件的核
心部分。Linux操作系统内核管理以下事...
Acegene IT Co. Ltd. 4
Linux功能
• 所有主要的网络协议
• 硬盘配额支持
• 全部的源代码
• 国际化的字体和键盘
• 作业控制
• 数学协处理器仿真
• 内存保护
• 多平台
• 多处理器
• 多用户
• 多任务
...
Acegene IT Co. Ltd. 5
GPL和Free
• Linux操作系统遵从GNU公共许可证
( GNU Public License,简称GPL)的规
定。
• Linux对外的一个重要的特点就是”Free”,
自由和免费。
Acegene IT Co. Ltd. 6
What is Linux?
• Linux is an operating system with the
following attributes:
– Multi-user
– Multi-ta...
Acegene IT Co. Ltd. 7
Is Linux the same as UNIX?
• The command set is similar
• They work the same
• They look the same
• ...
Acegene IT Co. Ltd. 8
Is Linux a real OS?
• Yes, absolutely
• Linux is used
– In mission critical applications
– Around th...
Acegene IT Co. Ltd. 9
Linux发行版本的概念
• 大多数的Linux操作系统的发行版本都使用标准
的Linux内核,但有时候也会稍微加以修改,这
个操作系统现在的规模已经变得相当庞大了,因
此许多人更愿意购买一张它的CD...
Acegene IT Co. Ltd. 10
谁使用Linux操作系统
• Linux正在逐渐赢得普通用户的青睐。但是它仍
然不是一个适用于普通大众的操作系统。对那些
习惯了当今鼠标界面操作系统的人们来说, 学习
仍是很困难的。需要学习一大套从...
Acegene IT Co. Ltd. 11
Enterprise vs. Retail
• Retail distributions
– Faster release cycles (4-6 months)
– Geared for home...
Linux Distribution Overview
• The core parts of a Linux system are:
– Linux kernel
– User space utilities and applications...
Linux Kernel
• Core component of the operating
system
– Configurable and tunable
– Provides main OS functions
• I/O, disk,...
Acegene IT Co. Ltd. 14
Kernel concepts
• Linux is based on a modular non-
microkernel architecture
– All device drivers sh...
• All components of the operating
system are delivered via RPM
packages
– Kernel
– System utilities
– Applications
• Both ...
Linux Updates
• Apply the recommended updates by
the distribution vendor:
– Most vendors provide automatic updates
• Red H...
Linux Enterprise Features
• Linux enterprise features support :
– Performance
– Scalability
– Reliability
Acegene IT Co. Ltd. 18
Symmetric Multiprocessing
• Fully multiprocessor capable (SMP)
– RHEL3: 16 processors
– SLES8: 32 p...
Acegene IT Co. Ltd. 19
Improved Memory Utilization
• Use more than 4GB of RAM on IA-32
– RHEL 2.1: max 16GB supported
– RH...
Acegene IT Co. Ltd. 20
Virtual Memory
• Each process has a private address space
– Keeps private data in memory secure
– P...
Virtual Filesystem (VFS)
• Linux supports multiple file systems
– OS is file system independent
– Multiple file systems ca...
Acegene IT Co. Ltd. 22
Filesystems
• Important ones to know:
– ext2/3 - Red Hat default (ext3)
– reiserfs - SLES8 default
...
Acegene IT Co. Ltd. 23
Filesystem Cache
• Buffers all filesystem I/O
– All filesystem I/O is copied to/from cache
buffers
...
Acegene IT Co. Ltd. 24
Process Disk file
Write
Read
Raw Devices
• Have traditionally been considered the
high performance ...
Acegene IT Co. Ltd. 25
Modular Drivers
• Loadable kernel modules (LKM)
• Can be unloaded/reloaded without
rebooting
• Modu...
I/O Modes
• Disk I/O can be performed in several
different modes
– Asynchronous vs. synchronous
– Direct vs. buffered
Proc...
Acegene IT Co. Ltd. 27
Storage Infrastructure
• Direct-attached storage (DAS)
– IDE, SCSI
– e.g., LSI Megaraid
• Network-A...
Acegene IT Co. Ltd. 28
Linux Clusters
• Scalable Shared Storage
– SCSI, SAN (FibreChannel), Firewire
(devel.)
• Must use r...
Acegene IT Co. Ltd. 29
Linux Kernel Enhancements
• Performance
– Asynchronous I/O
– Eliminate kernel locks
– Large SGA: > ...
Acegene IT Co. Ltd. 32
Summary
• Linux is
– An open-source fully featured operating
system
– Being adopted in the enterpri...
Q U E S T I O N S
A N S W E R S
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Linux操作系统01 简介

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  • If you have ever run any flavor of UNIX, you have a head start with Linux. For Windows users, the learning curve will be much greater.
  • All the UNIX commands you are familiar with work in Linux, such as cd, grep, ls,mkdir…
  • Transcript of "Linux操作系统01 简介"

    1. 1. Acegene IT Co. Ltd. 1 Linux操作系统 简介 周炯 上海艾基信息技术有限公司
    2. 2. Acegene IT Co. Ltd. 2 内容提要 • Linux简介 • Linux的安装 • SHELL及常用程序 • 文件编辑器vi • 目录和文件管理 • 文件系统管理 • 用户管理 • 网络管理 • 网络文件系统 • 模块安装和配置 • 系统管理 • 系统优化 • 开发工具 • Internet管理
    3. 3. Acegene IT Co. Ltd. 3 Linux——简介 • Linux操作系统是可以运行在许多不同类型的计 算机上的一种操作系统的“内核”。它是提供命 令行或者程序与计算机硬件之间接口的软件的核 心部分。Linux操作系统内核管理以下事情:比 如内存、采用什么方法以及在什么时候打开或者 关闭文件、哪一个进程或者程序可以获得计算机 的中央处理单元(CPU)等等。 • Linux操作系统可以说是UNIX操作系统的一个克 隆体,它最初是在1991年10月5日由它的作者 Linus Torvalds于赫尔辛基大学发布的。
    4. 4. Acegene IT Co. Ltd. 4 Linux功能 • 所有主要的网络协议 • 硬盘配额支持 • 全部的源代码 • 国际化的字体和键盘 • 作业控制 • 数学协处理器仿真 • 内存保护 • 多平台 • 多处理器 • 多用户 • 多任务 • 共享的库文件 • 支持多种文件系统 • 虚拟控制台 • 虚拟内存 • 其他更多功能
    5. 5. Acegene IT Co. Ltd. 5 GPL和Free • Linux操作系统遵从GNU公共许可证 ( GNU Public License,简称GPL)的规 定。 • Linux对外的一个重要的特点就是”Free”, 自由和免费。
    6. 6. Acegene IT Co. Ltd. 6 What is Linux? • Linux is an operating system with the following attributes: – Multi-user – Multi-tasking – Virtual memory system – X-Windows – Compatible with the IEEE POSIX.1 standard – Non-proprietary source code – Source code is available
    7. 7. Acegene IT Co. Ltd. 7 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
    8. 8. Acegene IT Co. Ltd. 8 Is Linux a real OS? • Yes, absolutely • Linux is used – In mission critical applications – Around the world • There are many flavors of Linux available – We call them: Distributions
    9. 9. Acegene IT Co. Ltd. 9 Linux发行版本的概念 • 大多数的Linux操作系统的发行版本都使用标准 的Linux内核,但有时候也会稍微加以修改,这 个操作系统现在的规模已经变得相当庞大了,因 此许多人更愿意购买一张它的CD-ROM光盘。每 一种发行版本彼此之间都稍微有一些差异,这些 差异主要表现在它们各自的安装程序包上,还表 现在安全性与可用性等方面侧重点的不同。把系 统内核、附带的工具程序及应用软件包等等打包 在一起,这样组成的一个Linux操作系统的集合 体就是我们说的某一种发行版本。
    10. 10. Acegene IT Co. Ltd. 10 谁使用Linux操作系统 • Linux正在逐渐赢得普通用户的青睐。但是它仍 然不是一个适用于普通大众的操作系统。对那些 习惯了当今鼠标界面操作系统的人们来说, 学习 仍是很困难的。需要学习一大套从未接触过的命 令,还需要学习与长期形成的概念不相同的那些 对待与处理事情的方法。对那些具有UNIX操作系 统使用经验的人们来说,Linux可是容易多了。 • 专业用户、系统管理员和计算机开发人员通常都 会比一般的用户更容易掌握Linux操作系统。但 就是对这些人来说,这方面的学习与实践也需要 有足够的耐心与专心。
    11. 11. Acegene IT Co. Ltd. 11 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 – Slower release cycles (12-18 months) – Longer support lifetimes (3-5 years) – Examples: RHEL3/4, SLES9 – Adds performance and scalability enhancements
    12. 12. Linux Distribution Overview • The core parts of a Linux system are: – Linux kernel – User space utilities and applications • The kernel and user space programs together make up the complete operating system
    13. 13. 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
    14. 14. Acegene IT Co. Ltd. 14 Kernel concepts • 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
    15. 15. • 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
    16. 16. Linux Updates • Apply the recommended updates by the distribution 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)
    17. 17. Linux Enterprise Features • Linux enterprise features support : – Performance – Scalability – Reliability
    18. 18. Acegene IT Co. Ltd. 18 Symmetric Multiprocessing • Fully 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
    19. 19. Acegene IT Co. Ltd. 19 Improved Memory Utilization • Use more than 4GB of RAM on IA-32 – RHEL 2.1: max 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 without swapping
    20. 20. Acegene IT Co. Ltd. 20 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 system to use more memory than any single space can address
    21. 21. 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
    22. 22. Acegene IT Co. Ltd. 22 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 Filesystem • ext2/3 and reiserfs are the most common • Use OCFS instead of raw devices in RAC
    23. 23. Acegene IT Co. Ltd. 23 Filesystem Cache • Buffers all filesystem I/O – All filesystem I/O is copied to/from cache buffers – By default, writes are not immediately flushed • Hardware I/O is deferred – Reads benefit from previous accesses as well as automatic read-ahead • May not need to perform a real hardware I/O • Made up of page cache and buffer cache – Page cache tends to be more heavily used • Reduced automatically when low on RAM
    24. 24. Acegene IT Co. Ltd. 24 Process Disk file Write Read Raw Devices • Have traditionally been considered the high performance solution – Bypasses the filesystem buffer cache – Moves larger buffers than file system I/Os • Requires more experienced administration
    25. 25. Acegene IT Co. Ltd. 25 Modular Drivers • Loadable kernel modules (LKM) • Can be unloaded/reloaded without rebooting • Modules provide: – Device drivers – File system drivers – System calls – Network drivers – Executable interpreters – Terminal device (TTY) drivers
    26. 26. I/O Modes • Disk I/O can be performed in several different modes – Asynchronous vs. synchronous – Direct vs. buffered Process Buffer cache Disk file Write Flush
    27. 27. Acegene IT Co. Ltd. 27 Storage Infrastructure • Direct-attached storage (DAS) – IDE, SCSI – e.g., LSI Megaraid • Network-Attached Storage (NAS) – NFS – e.g., Network Appliance Filer • Storage Area Networks (SAN) – FibreChannel – e.g., EMC Clariion
    28. 28. Acegene IT Co. Ltd. 28 Linux Clusters • Scalable Shared Storage – SCSI, SAN (FibreChannel), Firewire (devel.) • Must use raw devices or OCFS – Network Attached Storage (NFS) – LVM and software RAID (“md”) not cluster-aware • Linux includes cluster management software
    29. 29. Acegene IT Co. Ltd. 29 Linux Kernel Enhancements • Performance – Asynchronous I/O – Eliminate kernel locks – Large SGA: > 4 GB – Support more Oracle users • Stability – Graceful degradation under load • Manageability – (Remote) Crash Dump Facility – Configuration scripts
    30. 30. Acegene IT Co. Ltd. 32 Summary • Linux is – An open-source fully featured operating system – Being adopted in the enterprise arena today
    31. 31. Q U E S T I O N S A N S W E R S
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