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Frequently asked technical questions?

1. Explain the booting process in linux

The system BIOS checks the system and launches the first stage boot loader on the MBR of the primary hard disk.

The Frist stage boot loader loads itself into memory and launches the second stage boot loader from the /boot/partition.

The second stage boot loader loads the kernel into memory, which in turn loads any necessary modules and mounts the root partition read-only.

The kernel transfers control of the boot process to the /sbin/init program.

The /sbin/init program loads all services and user-space tools, and mounts all partitions  listed in /etc/fstab.

The user is presented with a login screen for the freshly booted Linux system.

2. Why is DNS important?

DNS is like a phone book for the Internet. If you know a person’s name but don’t know their telephone number, you can simply look it up in a phone book. DNS provides this same service to the Internet.

When you visit http://ipsrsolutions.com/ in a browser, your computer uses DNS to retrieve the website’s IP address. Without DNS, you would only be able to visit our website (or any website) by visiting its IP address directly.

3. What is LAMP

LAMP is an open source Web development platform that uses Linux as the operating system, Apache as the Web server, MySQL as the relational database management system and PHP as the object-oriented scripting language. (Sometimes Perl or Python is used instead of PHP.)

4. How secured is Linux? Explain.

Security is the most important aspect of an operating system. Due to its unique authentication module, Linux is considered as more secured than other operating systems. Linux consists of PAM. PAM is Pluggable Authentication Modules. It provides a layer between applications and actual authentication mechanism. It is a library of loadable modules which are called by the application for authentication. It also allows the administrator to control when a user can log in. All PAM applications are configured in the  directory “/etc/pam.d” or in a file “/etc/pam.conf”. PAM is controlled using the configuration file or the configuration directory.

5. What is the advantage of open source?

Open source allows you to distribute your software, including source codes freely to anyone who is interested. People would then be able to add features and even debug and correct errors that are in the source code. They can even make it run better, and then redistribute these enhanced source code freely again. This eventually benefits everyone in the community.

Content courtesy:
Mr. Szen John Providence
Corporate Trainer cum System Administrator, ipsr solutions ltd