Linux Cloud,Here the linux rain will never stop!!! Enjoy the Linux Rain.

Linux CBT- EL5 Edition- Rapidshare

2008-11-24T00:34:00.000-08:00

LinuxCBT Enterprise Linux 5 Edition focuses on the RedHat® Enterprise 5 GNU/Linux operating system. It is the successor to LinuxCBT EL-4 Edition.

LinuxCBT EL-5 Edition, is unparalleled in content, depth and expertise. LinuxCBT EL-5 Edition prepares you or your organization for successfully deploying and managing business-critical RedHat® Enterprise 5-based solutions. Let LinuxCBT EL-5 Edition teach you applicable GNU/Linux skills.

Recommended Prerequisites for:

LinuxCBT EL-5 Edition

Open mind & determination to master Linux and related open-source applications
Basic MS Windows skills
Basic understanding of networking concepts
Access to a PC to perform all of the installations and exercises

LINK:
http://rapidshare.com/files/138053519/keosoft90-L.C.E.L.5.E.part01.rar
http://rapidshare.com/files/138054500/keosoft90-L.C.E.L.5.E.part02.rar
http://rapidshare.com/files/138055382/keosoft90-L.C.E.L.5.E.part03.rar
http://rapidshare.com/files/138056168/keosoft90-L.C.E.L.5.E.part04.rar
http://rapidshare.com/files/138057290/keosoft90-L.C.E.L.5.E.part05.rar
http://rapidshare.com/files/138058526/keosoft90-L.C.E.L.5.E.part06.rar
http://rapidshare.com/files/138060916/keosoft90-L.C.E.L.5.E.part07.rar
http://rapidshare.com/files/138062107/keosoft90-L.C.E.L.5.E.part08.rar
http://rapidshare.com/files/138063194/keosoft90-L.C.E.L.5.E.part09.rar
http://rapidshare.com/files/138064192/keosoft90-L.C.E.L.5.E.part10.rar
http://rapidshare.com/files/138065089/keosoft90-L.C.E.L.5.E.part11.rar
http://rapidshare.com/files/138066818/keosoft90-L.C.E.L.5.E.part12.rar
http://rapidshare.com/files/138067591/keosoft90-L.C.E.L.5.E.part13.rar
http://rapidshare.com/files/138068870/keosoft90-L.C.E.L.5.E.part14.rar
http://rapidshare.com/files/138069723/keosoft90-L.C.E.L.5.E.part15.rar
http://rapidshare.com/files/138071877/keosoft90-L.C.E.L.5.E.part16.rar
http://rapidshare.com/files/138073193/keosoft90-L.C.E.L.5.E.part17.rar
http://rapidshare.com/files/138074030/keosoft90-L.C.E.L.5.E.part18.rar
http://rapidshare.com/files/138074860/keosoft90-L.C.E.L.5.E.part19.rar
http://rapidshare.com/files/138079739/keosoft90-L.C.E.L.5.E.part20.rar
http://rapidshare.com/files/138080622/keosoft90-L.C.E.L.5.E.part21.rar
http://rapidshare.com/files/138081597/keosoft90-L.C.E.L.5.E.part22.rar
http://rapidshare.com/files/138082669/keosoft90-L.C.E.L.5.E.part23.rar
http://rapidshare.com/files/138083352/keosoft90-L.C.E.L.5.E.part24.rar
http://rapidshare.com/files/138084133/keosoft90-L.C.E.L.5.E.part25.rar
http://rapidshare.com/files/138084897/keosoft90-L.C.E.L.5.E.part26.rar
http://rapidshare.com/files/138086100/keosoft90-L.C.E.L.5.E.part27.rar
http://rapidshare.com/files/138087007/keosoft90-L.C.E.L.5.E.part28.rar
http://rapidshare.com/files/138087679/keosoft90-L.C.E.L.5.E.part29.rar

Disclaimer Note:
Files are neither stored on my server nor uploaded by me.

Tip:How to Mount a ISO (CD image File) in Linux

2008-05-03T06:36:00.001-07:00

In linux its easy to mount the iso image with single command like

1) You must login as a root user, if not root user then switch to root user using following command:
$ su -
2) Create the directory aka mount point:
# mkdir -p /mnt/disk
3) Use mount command as follows (assumes that your ISO file name is disk1.iso):
# mount -o loop disk1.iso /mnt/disk
4) Change directory to list it:
# cd /mnt/disk
# ls -l
To Unmount
#umount /mnt/disk

LinuxCBT Mail Edition-RAPIDSHARE

2008-05-02T04:22:00.000-07:00

LinuxCBT Mail Edition focuses on the 3 leading Mail Transfer Agents (MTAs) and ancillary components:

Sendmail - LinuxCBT Sendmail Edition

Postfix - LinuxCBT Postfix Edition

qmail - LinuxCBT qmail Edition.

Linux/UNIX systems are responsible for moving the overwhelming majority of electronic mail across private and public networks. Consequently, savvy Systems Admins. are expected to have a solid foundation in MTAs and ancillary components for general and automated mail-based applications.

Let LinuxCBT Mail Edition help to solidify your understanding of key MTAs and ancillary components.

Recommended Prerequisites:

Familiarity with electronic mail concepts (MUA/MTA/etc.)

Access to a GNU/Linux-based PC to install the MTAs and ancillary components used

LINKS:

SENDMAIL EDITION

http://www.rapidshare.com/files/37651756/NZ_SE.rar
http://www.rapidshare.com/files/37659272/NZ_SE.r00
http://www.rapidshare.com/files/37656832/NZ_SE.r01
http://www.rapidshare.com/files/37658157/NZ_SE.r02
http://www.rapidshare.com/files/37646619/NZ_SE.r03
http://www.rapidshare.com/files/37649754/NZ_SE.r04
http://www.rapidshare.com/files/37649775/NZ_SE.r05

POSTFIX EDITION

http://www.rapidshare.com/files/37664192/NZ_PE.rar
http://www.rapidshare.com/files/37664683/NZ_PE.r00
http://www.rapidshare.com/files/37665904/NZ_PE.r01
http://www.rapidshare.com/files/37665466/NZ_PE.r02
http://www.rapidshare.com/files/37660568/NZ_PE.r03
http://www.rapidshare.com/files/37662021/NZ_PE.r04
http://www.rapidshare.com/files/37662450/NZ_PE.r05

QMAIL EDITION

http://www.rapidshare.com/files/37814161/NZ_QE.rar
http://www.rapidshare.com/files/37816183/NZ_QE.r00
http://www.rapidshare.com/files/37818162/NZ_QE.r01
http://www.rapidshare.com/files/37820258/NZ_QE.r02
http://www.rapidshare.com/files/37822844/NZ_QE.r03
http://www.rapidshare.com/files/37824895/NZ_QE.r04
http://www.rapidshare.com/files/37826710/NZ_QE.r05
http://www.rapidshare.com/files/37828215/NZ_QE.r06
http://www.rapidshare.com/files/37828310/NZ_QE.r07

PASSWORD: NeedZ

Introduction to Asterick PBX

2008-05-02T04:14:00.000-07:00

VTC-Red Hat Certified Engineer RHCE- RAPIDSHARE

2008-04-30T00:10:00.000-07:00

Introduction
Welcome (05:28)
System Requirements (02:54)

Additional Information for the RHCE Exam
What Else to prepare for the RHCE Exam (02:09)
Logical Volume Management (04:07)
Logical Volumes During Installation (06:00)
Logical Volumes After Installation Pt.1 (02:20)
Logical Volumes After Installation Pt.2 (06:09)
Setting up a Kickstart File (04:49)
An Automated Kickstart Installation (03:48)
Reviewing Rescue Mode (06:23)
Problems during the boot process (04:35)
What can go wrong with GRUB (07:36)
Create a network installation server (05:01)

System Monitoring and Fault Analysis
System Performance and Security Concepts (04:46)
System Faults and Breaches (05:00)
Method of Fault Analysis (03:03)
Benefits of System Monitoring (03:20)
Managing Process by Account (02:24)

System Service Analysis
System Service Access Controls (06:48)
Service and Network Access Controls (04:30)
Service and Application Access Controls (03:06)
tcp_wrappers Configuration (04:11)
Security Enhanced Linux (SELinux) (05:09)

Network Configuration and Security
Network Resource Access Controls (03:20)
Dynamic Interface Configuration (03:48)
Static Interface Configuration (03:10)
Routing Configuration Pt.1 (02:28)
Routing Configuration Pt.2 (05:52)
Netfilter Overview (06:11)
iptables Firewall Rules (06:09)
Firewall Rules by IP address (06:21)
Network Access Translation (NAT) (03:17)

Network Support Services
Organizing Networked Systems (02:08)
Host Name Resolution (03:07)
Trace a DNS Query with the dig command (02:47)
Exploring DNS with the host command (02:49)
An Overview of Domain Name Services (03:15)
DNS Packages (05:14)
Configuring a BIND Caching Nameserver (06:40)
Setting up a Slave Nameserver (05:17)
BIND in sysconfig and command support (04:04)
The DHCP Service (05:57)
Configuring an NTP Server (05:37)

Sharing on a Network
Network File Sharing Services (02:26)
FTP – Basic Server Configuration (05:05)
FTP – Security Options (06:09)
NFS – Basic Server Configuration (03:47)
NFS – Security Options (04:49)
Samba – Basic Server Configuration (06:10)
More on Samba (06:25)
Samba Security Options (03:59)
File Server Security (03:28)

Apache Web Services and More
Apache Web Services (03:02)
Critical Apache Configuration Directives (06:28)
Creating a Virtual Host (06:55)
Limiting Access to an Apache Website (05:33)
Apache and SELinux (03:39)
Creating a Secure Apache Host (07:24)
Configuring the Squid Web Proxy (05:27)

Configuring Email Services
Email Protocols and Agents (04:02)
Basic sendmail Configuration Pt.1 (04:33)
Basic sendmail Configuration Pt.2 (03:38)
Basic Postfix Configuration (04:33)
Switching Between SMTP Services (02:47)
Mail Retrieval Protocols (03:39)

Creating Secure Remote Access
A Secure Shell Server (06:17)
Configuring Secure Certificates (05:24)
Secure Shell Keys (07:10)

Account Security
Basic Account Management (03:02)
Name Service Switching (04:19)
Pluggable Authentication Modules (PAM) (04:19)
Utilities and Authentication (04:52)
Making PAM Work For You (05:57)

Troubleshooting and System Maintenance
Use the Rescue Environment (06:38)
Diagnose and Correct Boot Failures (06:04)
Address Problems with Network Services (06:04)
Add, Remove, and Resize Logical Volumes (03:22)
Diagnose SELinux Network Problems (02:32)

Installation and Configuration
Install Packages for Network Services (04:08)
Configure SELinux for Network Services (02:49)
Configure Services to Start on Boot (03:43)
Configure Basic Service Operation (03:29)
Configure User/Host-based Security (03:52)
Configure Kickstart Installations (02:45)
Add Logical Volumes during Installation (03:47)
Use iptables to for Firewalls and NAT (04:33)
Use PAM for User-Level Restrictions (03:35)

Wrap-up
Wrap-up Pt.1 (03:33)
Wrap-up Pt.2 (05:36)

Credits
About the Author (01:23)

LINKS:

http://rapidshare.com/files/85979120/VTC_Red_Hat_Certified_Engineer_RHCE.part1.rar
http://rapidshare.com/files/86729837/VTC_Red_Hat_Certified_Engineer_RHCE.part2.rar
http://rapidshare.com/files/86730147/VTC_Red_Hat_Certified_Engineer_RHCE.part3.rar
http://rapidshare.com/files/86729836/VTC_Red_Hat_Certified_Engineer_RHCE.part4.rar
http://rapidshare.com/files/86730215/VTC_Red_Hat_Certified_Engineer_RHCE.part5.rar
http://rapidshare.com/files/86730271/VTC_Red_Hat_Certified_Engineer_RHCE.part6.rar
http://rapidshare.com/files/86730267/VTC_Red_Hat_Certified_Engineer_RHCE.part7.rar

LINUXCBT NETWORK ADMINISTRATION- RAPIDSHARE

2008-04-29T23:48:00.000-07:00

* Discuss & demonstrate the usage of commonly used networking tools:
* PING - Demonstrate PING flooding of remote hosts - ICMP Attack Techniques
* PING - Cisco PIX Integration & Debugging of ICMP Echo Requests/Echo Replies
* Traceroute - Cisco PIX Integration & provisioning of ICMP traffic types
* MTR (PING & Traceroute functionality) plus Cisco PIX debugging of ICMP data flow
* ARP
* NETSTAT/LSOF
* IFCONFIG
* Route
* DIG & NSLOOKUP
* Whois
* Who, w, wc, last, cat, grep, vi, pico, head, tail, etc.
* Message of the day banners (MOTD), /etc/issue file (pre-login banner/display info.)

#
# Implement Dynamic Host Configuration Protocol (DHCP) services

* Explain the various steps of the DHCP process
* Configure global & scope-level DHCP options
* Configure IP reservations based on layer 2 MAC addresses
* Disable Cisco PIX DHCP services
* Enable Linux DHCP services
* Configure Windows 2003/XP/Linux clients to receive dynamic addresses from Linux

# Discuss Xinetd super server concepts and applications

* Identify services controlled by Xinetd
* Enable & disable Xinetd-controlled services & examine results
* Implement access control on Xinetd controlled services
* Implement Xinetd IP and port-level daemon redirection
* Discuss Xinetd & TCP Wrappers relationship and dual-layer security benefits

# Implement Very Secure VSFTPD File Transfer Protocol (FTP) services

* Implement anonymous FTPD
* Implement user-level FTPD access
* Implement FTPD banners
* Disable anonymous access
* Configure VSFTPD to run under the auspices of Xinetd super server for increased security
* Implement bandwidth rate-limiting to control bandwidth usage

# Discuss Linux & Windows Integration via Samba

* Install Samba support
* Install Samba Web-based Administration Tool (SWAT)
* Configure Samba file & print sharing
* Evaluate access to Samba file & print server
* Configure Samba Windows Internet Name Server (WINS) support
* Evaluate Windows XP/2003 client access to Samba-WINS server

# Discuss the Network File System (NFS) concepts and Linux support

* Implement the NFS daemon
* Review /etc/exports parameters and options
* Evaluate access to NFS exports
* Implement NFS connectivity across a WAN connection via IPSEC VPN-connectivity

# Discuss the CRON scheduling system concepts and application

* Identify various predefined CRON entries and schedules
* Define custom cron jobs system-wide
* Define custom cron jobs user-wide
* Evaluate results of cron jobs

# Implement the Berkeley Internet Daemon (BIND) Domain Name Server (DNS)

* Implement BIND 9.x
* Configure BIND as a caching-only DNS server
* Test caching-only name resolution from Windows 2003 & Linux hosts
* Secure access to caching-only/recursive name server via ACLs
* Configure BIND as a primary DNS server
* Test primary name resolution from Windows 2003 & Linux hosts
* Configure BIND as a secondary(slave) DNS server
* Restrict communications between primary & secondary DNS servers
* Implement updates between master and secondary DNS servers via IPSEC VPN
* Configure DNS zones on Linux BIND & Windows 2003 DNS - activate replication
* Implement poor man's load balancing using DNS round robin
* Evaluate results of BIND configuration using DIG
* Configure DNS zones
* Configure zone transfers
* Configure secure-zone transfers
* Evaluate BIND's configuration files named.conf & named.custom
* Configure BIND sub-domain delegation. i.e. internal.linuxcbt.net
* Configure BIND to support reverse domains
* Configure Linux/Windows 2003 clients to use Linux BIND DNS server
* DNS Transaction Signatures (TSIG) implemenation
* Identify BIND logging information for troubleshooting purposes
* Configure BIND DNS with IP Aliasing (Sub-Interfaces) to host DNS on separate IP address

# Implement Network Monitoring & Graphing tools using SNMP, etc.

* Implement Multi Router Traffic Grapher (MRTG)
* Graph Cisco Firewall with MRTG
* Implement Cacti Network Graphing Tool
* Download and Install Cacti and required components (RRDTool, MySqL, etc.)
* Explore Cacti Interface, options, etc.
* Graph Cisco, Linux & Windows 2003 resources with Cacti using SNMP & Scripts

# Implement Network Time Protocol (NTP) & Time Synchronization services for local subnets

* Discuss features and distributed nature of the hierarchial NTP service
* Ascertain and select optimal Stratum 1 NTP servers for synchronization
* Review default NTP configuration
* Configure NTP to synchronize with NTP servers
* Configure internal Linux clients to syncrhonize with internal Stratum 2 NTP server
* Configure Cisco PIX firewall to synchronize with internal Stratum 2 NTP server
* Use NTP-related tools such as NTPQ, NTPTRACE to ascertain NTP-related information

LINKS:

http://rapidshare.com/files/56422679/LX-CB-NET-AD.part7.rar
http://rapidshare.com/files/56421776/LX-CB-NET-AD.part4.rar
http://rapidshare.com/files/56421108/LX-CB-NET-AD.part5.rar
http://rapidshare.com/files/56421007/LX-CB-NET-AD.part6.rar
http://rapidshare.com/files/56420363/LX-CB-NET-AD.part2.rar
http://rapidshare.com/files/56420289/LX-CB-NET-AD.part3.rar
http://rapidshare.com/files/56420278/LX-CB-NET-AD.part1.rar

LINUX CBT MAIL EDITION-RAPIDSHARE

2008-04-29T23:43:00.000-07:00

LinuxCBT Mail Edition focuses on the 3 leading Mail Transfer Agents (MTAs) and ancillary components:

1. Sendmail - LinuxCBT Sendmail Edition

2. Postfix - LinuxCBT Postfix Edition

3. qmail - LinuxCBT qmail Edition.

Linux/UNIX systems are responsible for moving the overwhelming majority of electronic mail across private and public networks. Consequently, savvy systems Admins. are expected to have a solid foundation in MTAs and ancillary components for general and automated mail-based applications.

Let LinuxCBT Mail Edition help to solidify your understanding of key MTAs and ancillary components.

Recommended Prerequisites:

1- Familiarity with electronic mail concepts (MUA/MTA/etc.)

2- Access to a GNU/Linux-based PC to install the MTAs and ancillary components used

LINK:

http://rapidshare.com/users/5N6I8X

VTC-APACHE WEB SERVER

2008-04-29T23:18:00.000-07:00

Behind every great web site is a hard working web server ready to deliver content to the world. Apache is the most widely used web server software on the Internet, combining power and flexibility in an open source package. VTC author Dawn Dunkerley will guide you through the numerous features of Apache and the LAMP stack, helping you configure a web server solution that works for your needs. To begin learning simply click the links.

LINKS:

http://rapidshare.com/users/25QHX1

Password: knowfree.net

LINUX CBT SAMBA EDITION-RAPIDSHARE

2008-04-29T23:12:00.000-07:00

LinuxCBT Samba Edition focuses on the Samba suite of clients and servers and Windows integration.

Samba is the de-facto UNIX/Linux-based software for seamlessly integrating UNIX/Linux environments with MS Windows networks via Samba's implementation of the SMB protocol suite. Samba allows your UNIX/Linux system to emulate a Windows workstation/server in the network neighborhood/my network places browse list. Consequently, your UNIX/Linux-based system appears to be a Windows-based system featuring file & print shares. Additionally, Samba adds many features not included with stock MS Windows systems.

Let LinuxCBT Samba Edition help to solidify your understanding of Samba and ancillary components.

Recommended Prerequisites:

Familiarity with MS Windows networking (File & Print shares)

Access to a GNU/Linux-based PC to install Samba and ancillary components used

Access to a MS Windows-based system connected to the same network

LINK:

http://rapidshare.com/users/X1P7LG

LinuxCBT Security Edition- RAPIDSHARE

2008-04-29T22:59:00.000-07:00

LinuxCBT Security Edition encompasses 8 pivotal security modules:
1.Security Basics (fundamentals)

2.Proxy Security featuring Squid

3.Firewall Security featuring IPTables

4.SELinux Security - MAC-based Security Controls

5.Network Intrusion Detection System (NIDS) Security featuring SnortÂ® NIDS

6.Packet Capture Analysis Security featuring EtherealÂ®

7.Pluggable Authentication Modules (PAM) Security

8.Open Secure Shell version 2 (OpenSSHv2) Security

LinuxCBT Security Edition is unparalleled in content, depth and expertise. It entails 80-hours, or ~ 2-weeks of classroom training. LinuxCBT Security Edition prepares you or your organization for successfully securing GNU/Linux & Open Source-based solutions. As a by-product, many of the covered concepts, utilities and tricks are applicable to heterogeneous computing environments, ensuring your coverage of the fundamentals of securing corporate infrastructures.

LINKS:

http://rapidshare.com/files/69018648/LinuxCBT_Security.part01.rar

http://rapidshare.com/files/69031883/LinuxCBT_Security.part02.rar

http://rapidshare.com/files/69005471/LinuxCBT_Security.part03.rar

http://rapidshare.com/files/69873629/LinuxCBT_Security.part04.rar

http://rapidshare.com/files/69885431/LinuxCBT_Security.part05.rar

http://rapidshare.com/files/69897944/LinuxCBT_Security.part06.rar

http://rapidshare.com/files/69909802/LinuxCBT_Security.part07.rar

http://rapidshare.com/files/69922688/LinuxCBT_Security.part08.rar

http://rapidshare.com/files/69935795/LinuxCBT_Security.part09.rar

http://rapidshare.com/files/70093624/LinuxCBT_Security.part10.rar

http://rapidshare.com/files/70103545/LinuxCBT_Security.part11.rar

http://rapidshare.com/files/70113868/LinuxCBT_Security.part12.rar

http://rapidshare.com/files/69862357/LinuxCBT_Security.part13.rar

http://rapidshare.com/files/70125288/LinuxCBT_Security.part14.rar

http://rapidshare.com/files/70139621/LinuxCBT_Security.part15.rar

http://rapidshare.com/files/70155005/LinuxCBT_Security.part16.rar

http://rapidshare.com/files/70083807/LinuxCBT_Security.part17.rar

http://rapidshare.com/files/70700579/LinuxCBT_Security.part18.rar

http://rapidshare.com/files/70707140/LinuxCBT_Security.part19.rar

http://rapidshare.com/files/70712999/LinuxCBT_Security.part20.rar

http://rapidshare.com/files/70718575/LinuxCBT_Security.part21.rar

http://rapidshare.com/files/70724515/LinuxCBT_Security.part22.rar

http://rapidshare.com/files/71258733/LinuxCBT_Security.part23.rar

http://rapidshare.com/files/70693263/LinuxCBT_Security.part24.rar

LinuxCBT DBMS Edition (MySQL 5) RAPIDSHARE

2008-04-29T22:53:00.000-07:00

LinuxCBT DBMS Edition feat. MySQL 5 focuses on the ubiquitous, high-performance, low-maintenance, highly-available and scaleable MySQL 5 Database Management System (DBMS).
LinuxCBT DBMS Edition establishes the foundation for successful deployments and administration of MySQL 5 by exploring many of its features including but not limited to DML & DDL Statements, Terminal Monitor, shell-based clients, graphical clients, MyODBC, storage engines, data imports & exports, and PHP integration.
LinuxCBT DBMS Edition is unparalleled in content, depth and expertise. It entails 30-hours, or 4+ days of classroom training. LinuxCBT DBMS Edition prepares you for successfully deploying MySQL-based DBMS solutions.
Let LinuxCBT DBMS Edition cost-effectively sharpen your MySQL 5 DBMS skills!
Recommended Prerequisites for:
* Any LinuxCBT Operating System Course /ClassicEL-4SUSEDebian Editions/o Open mind & determination to master Linux and related open-source applicationso Basic understanding of networking conceptso Access to a PC to follow the exercises

LINK:

http://rapidshare.com/users/18HWZT

LINUX CBT SCRIPTING EDITION-RAPIDSHARE

2008-04-29T22:50:00.000-07:00

VI/VIM Editior

2008-04-27T23:39:00.000-07:00

All Linux configuration files are written in plain English, easy to read and to adapt. You use a text-editor to write or make changes to such files. The two most popular, powerful, and unfortunately "difficult" text editors, both of which are found in every Linux distro, are Vi and Emacs.
Most GUI-based editors, such as Kedit, are easier to manage. But don't make the mistake of thinking that a GUI-based editor is all you need. There are situations that crop up with Linux that require a text-mode editor -- in other words, when you don't have the luxury of accessing a GUI desktop at all. Vi and Emacs are the only tools that come with every Linux distro that work in text mode, so learning one or the other is mandatory.
The advantage of learning vi and learning it well is that one will find vi on all Unix based systems and it does not consume an inordinate amount of system resources. Vi works great over slow network ppp modem connections and on systems of limited resources. One can completely utilize vi without departing a single finger from the keyboard. (No hand to mouse and return to keyboard latency)
The vim editor is an enhanced version of vi. The improvements are clearly noticed in the handling of tags.
The vi editor has three modes, command mode, insert mode and command line mode.
Command mode: letters or sequence of letters interactively command vi. Commands are case sensitive. The ESC key can end a command.
Insert mode: Text is inserted. The ESC key ends insert mode and returns you to command mode. One can enter insert mode with the "i" (insert), "a" (insert after), "A" (insert at end of line), "o" (open new line after current line) or "O" (Open line above current line) commands.
Command line mode: One enters this mode by typing ":" which puts the command line entry at the foot of the screen.
Terminate session:
Use command: ZZ

Save changes and quit.
Use command line: ":wq"

Save (write) changes and quit.
Use command line: ":w"

Save (write) changes without quitting.
Use command line: ":q!"

Ignore changes and quit. No changes from last write will be saved.
Use command line: ":qa"

Quit all files opened.
Example:
Consider you want to create a normal file, named as “examplefile”.
]# vi examplefile
To write in this file, Press “Insert” key or “i”
To select the complete line and copy Press “yy” and for paste Press “p”, Make sure you are not in interesting mode.
To save file after writing, Press “Esc” and then “:s” for save and “:q” for quit
To save and quit with single command Press “Shift+zz”
To quit without saving just type “:q!”

VI editior show garbage values

2008-04-27T23:29:00.000-07:00

Sometimes, while working in vi editior you press “Ctrl+zz” instead of “Shift+zz” to save and exit. By doing this,VI editior immediately stop and exit. This mistake will make a garbage file with “swp” extension. And you file will be shown as corrupted or not shown in simple “ls” command. To resolve this, first check the hidden file list, there you will a file something like “.examplefile.swp”
]#ls –a

Just remove the files with swp extension and your problem solved
]#rm *.swp

2008-04-27T23:14:00.000-07:00

Linux Directory Structure:

1-“/” (The root directory):
The starting point of your directory structure, this is where the Linux system begins. Every other file and directory on your system is under the root directory. Usually the root directory contains only subdirectories, so it's a bad idea to store single files directly under root.
Don't confuse the root directory with the root user account, root password (which obviously is the root user's password) or root user's home directory.
2- “/bin”or “/usr/bin”: (binaries programs)
These two directories contain a lot of programs (binaries, hence the directory's name) for the system. The /bin directory contains the most important programs that the system needs to operate, such as the shells, ls, grep, and other essential things. /usr/bin in turn contains applications for the system's users. However, in some cases it really doesn't make much difference if you put the program in /bin or /usr/bin.
3- “/boot”:
As the name suggests, this is the place where Linux keeps information that it needs when booting up. For example, this is where the Linux kernel is kept. If you list the contents of /boot, you'll see a file called vmlinuz - that's the kernel.
4- “dev”:
The devices that is available to a Linux system. Remember that in Linux, devices are treated like files and you can read and write devices like they were files. For example, /dev/fd0 is your first floppy drive, /dev/cdrom is your CD drive, /dev/hda is the first IDE hard drive, and so on. All the devices that a Linux kernel can understand are located under /dev, and that's why it contains hundreds of entries.
5- “/etc”:
The configuration files for the Linux system. Most of these files are text files and can be edited by hand. Some interesting stuff in this directory:
/etc/inittab:A text file that describes what processes are started at system bootup and during normal operation. For example, here you can determine if you want the X Window System to start automatically at bootup, and configure what happens when a user presses Ctrl+Alt+Del.
/etc/fstab:this file contains descriptive information about the various file systems and their mount points, like floppies, cdroms, and so on.
/etc/passwd:A file that contains various pieces of information for each user account. This is where the users are defined.
6-“/home”:
This is where users keep their personal files. Every user has their own directory under /home, and usually it's the only place where normal users are allowed to write files. You can configure a Linux system so that normal users can't even list the contents of other users' home directories.
7-“/lib”:
The shared libraries for programs that are dynamically linked. The shared libraries are similar to DLL's on Windows.
8-“/lost+found”:
Here Linux keeps the files that it restores after a system crash or when a partition hasn't been unmounted before a system shutdown. This way you can recover files that would otherwise have been lost.
9-“mnt”:
This directory is used for mount points. The different physical storage devices (like the hard disk drives, floppies, CD-ROM's) must be attached to some directory in the file system tree before they can be accessed. This attaching is called mounting, and the directory where the device is attached is called the mount point.
10-“proc”:
This is a special directory. Well, actually /proc is just a virtual directory, because it doesn't exist at all! It contains some info about the kernel itself. There's a bunch of numbered entries that correspond to all processes running on the system, and there are also named entries that permit access to the current configuration of the system. Many of these entries can be viewed.
11-“/media”:
Directory for mounting files systems on removable media like CD-ROM drives, floppy disks, and Zip drives.
12-“/root”:
The super user’s (root's) home directory, don’t confuse this with the root directory (/) of a Linux system.
13-“/sbin”or “/usr/sbin”:
Most system administration programs are stored in these directories. In many cases you must run these programs as the root user.
14-“/tmp”:
Programs can write their temporary files here
15-“usr”:
This directory contains user applications and a variety of other things for them, like their source codes, and pictures, docs, or config files they use. /usr is the largest directory on a Linux system, and some people like to have it on a separate partition. Some interesting stuff in /usr:
/usr/docDocumentation for the user apps, in many file formats.
/usr/shareConfig files and graphics for many user apps.
/usr/srcSource code files for the system's software, including the Linux kernel.
/usr/includeHeader files for the C compiler. The header files define structures and constants that are needed for building most standard programs. A subdirectory under /usr/include contains headers for the C++ compiler.
/usr/X11R6The X Window System and things for it. The subdirectories under /usr/X11R6 may contain some X binaries themselves, as well as documentation, header files, config files, icons, sounds, and other things related to the graphical programs.
/usr/local
This is where you install apps and other files for use on the local machine. If your machine is a part of a network, the /usr directory may physically be on another machine and can be shared by many networked Linux workstations. On this kind of a network, the /usr/local directory contains only stuff that is not supposed to be used on many machines and is intended for use at the local machine only.
Most likely your machine isn't a part of a network like this, but it doesn't mean that /usr/local is useless. If you find interesting apps that aren't officially a part of your distro, you should install them in /usr/local. For example, if the app would normally go to /usr/bin but it isn't a part of your distro, you should install it in /usr/local/bin instead. When you keep your own programs away from the programs that are included in your distro, you'll avoid confusion and keep things nice and clean.
16- “/var”:
This directory contains variable data that changes constantly when the system is running. Some interesting subdirectories:
/var/logA directory that contains system log files. They're updated when the system runs, and checking them out can give you valuable info about the health of your system. If something in your system suddenly goes wrong, the log files may contain some info about the situation.
/var/mailIncoming and outgoing mail is stored in this directory.
/var/spoolthis directory holds files that are queued for some process, like printing.
17-“srv”:
Contains data for services (HTTP, FTP, etc.) offered by the system.
18-“opt”:
Optional software packages copy/install files here.
19- “sys”:
A special directory that contains information about the devices as seen by the Linux kernel.

Breaking/Resetting the GRUB Password

2008-04-27T22:42:00.000-07:00

Breaking/Reset the Root password: (OS: Centos 4.1 )

1-Reboot/start the system
2-On welcome screen, press “e” while selecting the Linux OS (If you have grub password then first press “p” to give grub password and then press “e”)
3-You will see a new screen with three option select the following options
Kernel /vmlinuz-2.6.9-11.El ro root=LABEL= /rhgb quiet
4-selecting the following option, press “e” again
5-Write “-s” at the end of the above line and press Enter.
6-Now press “b”. System will boot on run level 1.
7-Just type “passwd” to change the root password. It will not ask the old root password

Breaking the Grub password:

1-Boot the system with the first Linux CD.
2-At the boot prompt, type Linux rescue to switch to rescue mode.
3-In rescue mode you will be asked if similar steps should be followed, which need to be followed in the installation.
4-Once you get the # prompt, type the following command:# chmod /mnt/sysImage
5-Edit the “/etc/grub.conf” file and remove the “password --md5 ” from the file. Save the file and exit.
6-Once your machine reboots, you will be able to start your Linux OS in the usual manner.