System Administeration Basics

System Administration Basics Session 3 By: Bahaa S. Salama (bahaa2008)

Agenda
Users Administration
Permissions
Partitions
Booting process
Processes
Applications
Networking Basics

Important Files
/etc/passwd /etc/shadow /etc/group /etc/gshadow

Users Administration
Add user useradd Delete user userdel Modify user usermod Change/Set password passwd Display logged in users who Display effective user whoami Display real/effective id id

User Administration cont.
Who is login/what is he doing w Current logged in users users Message all users wall Add group groupadd Delete group groupdel Modify group groupmod Groups that I'm memer in groups

Permissions
Why Permissions ?
User,Group,Other
Read,Write,Execute
Permissions symbolically
r read u user
w write g group
x execute o other

Permissions - cont.
Permissions numerically
7 rwx 3 -wx 6 rw- 2 -w- 5 r-x 1 --x 4 r-- 0 ---
Change user chown
Change group chgrp
Change permissions chmod

Partitions Information
List Partition fdisk -l
Partion Editor fdisk /dev/sda
-n add new partition
-d delete partition
-l list partition
-a add bootable flag

Disk space
File System usage df
File Space usage du
-s summerize
-h human readable

Mounting Partitions
List current mounts mount
Mount partitions
mount -t fstype -o options device dir
Examples
mount -t vfat /dev/sda1 /media/sda1
Unmount umount device
umount /dev/sda1

/etc/fstab
File Syntax
<file system> <mount point> <type> <options>
UUID vs devices

Processes Management
List processes ps aux
Kill process
kill by pid kill -9 pid
kill by name killall prog_name
Processes tree pstree
Top processes top

Boot Process
BIOS - Boot Sequence
Stage 1 bootloader (MBR)
Stage 2 bootloader (Grub,LILO, etc)
Kernal (linux kernel)
Init (starting userspace applications)

Boot loader
Grub
Installation
/boot/grub/menu.lst
Splash screen
Timeout
Default option
Other Systems
Kernel && init

Init Runlevels
0 halt 1 single-user mode 3 multi-user mode 5 multi-user mode + X-based login screen 6 reboot

Init Scripts
Understanding init scripts
/etc/init.d/
How to use init scripts
Start
Stop
Restart
Reload
Status

Installing Applications
Installation Methods
From source
Using Package mangers
Using Package utilites

Installing from source
Get the source
Get dependencies
Installing dependencies
Installing the application
Installation Process
./configure && make && make install
Uninstallation Process
make uninstall && make clean

Package Managers
/etc/apt/sources.list
/etc/apt/sources.list.d/
Apt-get
-install
-remove
-purge
Apt-cache
-search

Package Utilities
dpkg
-i install .deb package
-r remove .deb package
-l list installed packages
--reconfigure reconfigure package

Configuring Network Interface
Display interfaces ifconfig -a Set ip manually ifconfig eth0 <ip> Get ip automatic dhclient eth0 Set default route route add def gw <ip> eth0 Set wireless ap iwconfig eth1 essid <name> Set DNS Servers in /etc/resolv.conf (demo)

Questions

Thanks

http://www.eglug.fabrider.net	57
http://eglug.org	42
http://www.eglug.org	13
http://eglug.fabrider.net	4
http://www.slideshare.net	3
http://test.eglug.org	1

System Administeration Basics

by Bahaa Salama on Sep 01, 2009

Accessibility

Categories

Tags

Upload Details

Usage Rights

6 Embeds 120

Statistics

System Administeration Basics — Presentation Transcript