Tutorial on Linux Introduction, Installation & Initial Setups

1. Tutorial on Linux Introduction, Installation & Initial Setups Speaker: Faran Javed (BIT-5) Abdul Lateef Khan (BIT-5)

2. Agenda • Introduction • Planning to Install • Installing Red Hat Linux • Post Installation Configuration • First Steps with Linux

3. Part – IGetting Started

4. Introduction • For x86 architecture • Free implementation of UNIX • Used for • Programming • Productivity • Distributed Computing • Telecom & Networking

5. What is Linux ?

6. The core kernel of a free operating system first developed and released to the world by Linus Bendict Torvalds in 1991

7. What’s Red Hat Linux ?

8. Product of Red Hat Inc. • Named after a Cornell university team hat. • Objective: • Develop release and market an easily managed, and easy to use Linux Distribution

9. Brief History • Initiated by Linux Torvalds • Initially the little Clone of Unix • Version 0.0.1 was never announced • Version 0.0.2 announced October 5 1991 • Aim was to build a MINIX look-a-like OS for AT 386 machines

10. System Features • complete multitasking, multi-user operating system • Complete Implementation of the TCP/IP stack and other networking software is provided • Variety of File systems supported • Ext2 • Ext3 • XENIX and UNIX System V • Microsoft MS-DOS • Windows 95 VFAT file systems on a hard drive or floppy. • The ISO 9660 CD-ROM file system is also supported.

11. System Features • The kernel supports demand-paged, loaded executables. • Only those segments of a program which are actually in use are read into memory from disk. • unified memory pool for user programs and disk cache. • All free memory is used by the cache, which is reduced when running large programs. • Executables use dynamically linked, shared libraries

12. System Features • To facilitate debugging, the kernel generates core dumps for post-mortem analysis. • amount of available memory, Linux also implements disk paging • If several instances of a program are running at once, they share physical memory, which reduces overall usage.

13. Software Features • Coming Up in Later Slides

14. Preparing To InstallLinux

15. Linux Installation • Hardware Compatibility • http://hardware.redhat.com/hcl/ • Disk Space • 400 MB – 5 GB depending on minimal, personal, server etc. settings

16. Preparing for the Install Process • Most Common Installation Methods • CD-ROM • NFS • From a remotely mounted hard drive containing the red hat Linux software • FTP • HTTP • Hard Drive Partition

17. Preparing to Install from a CD-ROM • Just make sure System BIOS is set to BOOT from CD_ROM

18. Partitioning Your Hard Disk Space • If Linux is the only OS than we can auto partition • Assuming a machine with 20 GB Hard Disk & 256 MB RAM • Most basic Scheme Requires a native root partition & a swap partition

19. Typical Partitions • For a machine with only Linux on the system the scheme will look like: • Hard Drive Partition Mount Point Size /dev/hda1 / 19.14 GB /dev/hda2 swap 512 MB • For a machine already having windows: • Hard Drive Partition Mount Point Size /dev/hda1 /mnt/dos 9.74 GB /dev/hda2 / 8.14 GB /dev/hda3 swap 512 MB

20. Hosting Parts of the Linux File System on Partitions • /home • Our users home – will contain our personal files, • /opt • Directory for additional software packages to be installed • /tmp • Used as temporary storage for users • /usr • Holds nearly all software on the red hat system • /var • Security logs, mails, print spools are under this directory

21. Kickstart Installation Method • Automation always saves time • Use Red Hats KickStart Configurator • A sample ks.cfg file #System Language Lang en-US #Langugae Modules to Install Langsupport en_US

22. Sample File # System Keyboard keyboard us # System mouse Mouse genericps/2 # System time zone Timezone –utc America/NewYork # Root password Rootpw – iscrypted $1$shaldsgfakd3452435gjAJHSGDA/SAD324

23. The Installation Process • Language Selection • Keyboard and Mouse configuration • Choice of installation type • Personal Desktop • If new to the world of Linux • Workstation • If you would like a graphical desktop environment, as well as software development tools • Server • If you would like your system to function as a Linux-based server • Custom • Greatest flexibility • Upgrade

24. Installation Process (cont.) • Disk partitioning • Automatic Partitioning • Manual Partitioning • ext2, ext3, RAID, swap, vfat etc. • Configuring Boot Loader • LILO • GRUB • Network Configuration • Firewall Configuration • Language & Time Zone Configuration

25. Installation Process (cont.) • Authentication setup • Package Selection • Actual installation • Boot Disk creation, VGA and monitor configuration

26. First Steps In Linux

27. Viewing the red hat Linux file system • Ls • Tree

28. Basic Linux Directories • / The root Directory • /bin Essential Commands • /boot Boot Loader Files • /dev Device Files • /etc System Configuration files • /home User home directories • /lib Shared libraries • /mnt usual mount point • /opt Add-on software packages • Proc Kernel Information Process control • /root Super user • /sbin System commands mostly root only • /tftpboot Network boot support • /tmp temp files • /Usr Secondary software file hierarchy • /var Variable data (e.g. logos), spooled files

29. Files in the /etc directory • Fstab • FILE SYSTEM TABLE. A text file listing each hard drive, Floppy drive or other storage attached to your PC. • Inittab • The system Initialization table. Defines default run level. Here we can define either to use text or GUI mode. • Modules.conf • Contains directions and options used when loading kernel modules to enable various types of hardware • Passwd • The list of users of the system & their accnt info. • Printcap • Systems printer capabilities database • Shells • A list of approved shells (command line interfaces) • Sysconfig • Tree –afx /etc/sysconfig

30. Interact with the kernel • Use the proc diractory • Vi /proc/meminfo • Or use the free command • /proc/cpu -- cpu family,type & speed • /proc/net – important networking info • /proc/net/netstat , /proc/net/route , /proc/net/dev • /proc/version – kernel version

31. Remote Login • Use SSH – secure shell • Linux also supports : • Telnet • Rlogin

32. Changing user Information • Chfn – change finger information • Finger – get finger information

33. Accessing Documentation • Apropos partition • Will display related commands

34. Using the Man pages • Man rm • Will display manual pages for the rm command

35. Grep • Grep alateef /etc/passwd • This will search for alateef in /etc/passwd • Whereis fdisk

36. Using Environment Variables • PWD – current directory • USER – declare user name • LANG – To set language defaults • SHELL – TO declare the name and location of the current shell • PATH – set default location of executable files • LD_LIBRARY_PATH – location of important software libraries • TERM – set the type of terminal in use • MACHINE – declare system type, architecture & so on • $env • /etc/profile

37. Navigating & searching with shell • Cd /home/….. • Cd .. • Whereis • Locate • Apropos • Cat <filename>– contents of file • Less <filename> - allows scrolling while reading contents of file name • Mv <file1> <file2> • Mv <file> <dir> • Cp <src> <dst> • Rm <file> • Rmdir <dir> • Grep <string> <file>

38. Compressing & Decompressing Files • Bunzip2 - expands a compressed file • Bzip2 – compresses or expands files & directories • Gunzip • Gzip • Shar • Tar • unshar

39. Using Text Editors • Ed • Emacs • Jed • Joe • Mcedit • Pico • Sed • Vim • Vi • Gedit • Kate • Kedit • Nedit • kwrite

40. Working with vi • H,j,k,l – cursor movement • Delete character – x • Delete line – dd • Mode toggle – ESC, Insert (or i) • Quit - :q • Quit without saving - :q! • Save file - :w • Text search - / • Run a shell command - :sh (use exit to return)

41. Mounting a Drive

42. Compiling a simple C Program

43. Internet Configuration

44. Ethernet Configuration • Things you should know • IP address • If you're configuring loopback mode, it is 127.0.0.1 • Subnet mask • It is always 255.0.0.0 for loopback address • Broadcast address • It is equal to your subnet address with 255 replaced as the host address • IP address of Gateway • IP address of Name server

45. Configuration using system scripts • Edit the file /etc/sysconfig/network-scripts/ifcfg-eth0 DEVICE=eth0 ONBOOT=yes BOOTPROTO=static IPADDR=192.168.8.139 NETMASK=255.255.255.0 BROADCAST=192.168.8.255 GATEWAY=192.168.8.1 • Edit the file /etc/sysconfig/network NETWORKING=yes HOSTNAME=linux.niit.edu.pk GATEWAY=192.168.8.1

46. Configuration of Static IP via command line • The shell provides two programs for NIC configuration, ifconfig & route • ifconfig • For configuring the network device interface with certain parameters, such as the IP address, subnetwork mask etc. • Remember to bring the interface down & up when modifying • Set IP Address ifconfig lo 127.0.0.1 ifconfig eth0 192.168.75.20 netmask 255.255.255.0 • Verify Settings ifconfig eth0 • route • To show and manipulate the IP routing table • Add default gateway route add default gw 192.168.1.254 route add –net 192.156.79.0 netmask 255.255.255.0 dev eth0

47. Important Configuration files • /etc/hosts • Contains a list of IP addresses and the hostnames they correspond to 127.0.0.1 ENT localhost.localdomain localhost • /etc/networks • lists the names and addresses of your own and other networks • Used by the route command and allows you to specify a network by name instead of by address default 0.0.0.0 # default route - mandatory loopnet 127.0.0.0 # loopback network - mandatory niit-net 202.83.166.171 # Modify for your own network address

48. Important Configuration files • /etc/host.conf • Specifies how your system resolves hostnames order hosts,bind • /etc/resolv.conf • Configures the name resolver • specifies the address of your nameserver (if any) • domains that you want to search by default if a specified hostname is not a fully specified hostname domain niit.edu.pk nameserver 10.10.10.1

49. Network Configuration for DHCP • Edit the file /etc/sysconfig/network-scripts/ifcfg-eth0 DEVICE=eth0 ONBOOT=yes BOOTPROTO=dhcp IPADDR= NETMASK= BROADCAST= GATEWAY= • Edit the file /etc/sysconfig/network NETWORKING=yes HOSTNAME= GATEWAY=

50. Basic PPP Configuration for Modems • In Windows, modems and other serial devices are named COM1, COM2 etc. • In Linux, these are referred as /dev/ttyS0, /dev/ttyS1 • At installation time a symbolic link called /dev/modem will be created for the modem • KDE graphical tool called “kppp” configures a dialup connection easily • Located in /usr/bin/kppp • Red Hat requires the root password to be entered each time kppp is executed for security reasons • Some distributions allow any user to execute this program such as SuSE