Top 10 Linux Interview Questions With Answers

The article "Top 10 Linux Interview Questions With Answers" is very much helpful for the job seekers in Linux Admin.

1. Define Linux?

Ans: The operating system that is based on UNIX is known as LINUX. This operating system is completely based on Linux Kernel and it can be run on different hardware platforms that are perfectly manufactured by MIPS, IBM, Intel, Motorola and SPARC. Mascot is the other famous element in Linux.

2. Define LILO?

Ans: LILO stands for Linux boot loader. It will load the master boot record into the memory, and tell the system which separation and hard drive to boot from.

3. Name some basic components of LINUX?

Ans: Usually, it is like other operating system, LINUX has specific components like kernel, system utilities, shells and GUIs, application program. What makes LINUX useful when compared to other operating systems is all aspects with some extra features and codes can be downloaded for free.

4. Define ephemeral port in UNIX?

Ans: Ephemeral ports are port used by Operating system for consumer sockets. There is a specific range on which OS can open any port particular by ephemeral port range.

5. Define GRUB?

Ans: GNU GRUB is a Multiboot boot loader. GRUB stands for GRand Unified Bootloader, which was originally designed and executed by Erich Stefan Boleyn. In brief, a boot loader is the first software program that runs when a computer starts. It is liable for loading and transferring control to the operating system kernel software. 

6.  Define CVS? Name some useful CVS commands?

Ans: CVS is Concurrent Version System. It is the front end to the RCS revision control system which extends the concept of revision control from a collection of files in a single directory to a hierarchical collection of directories consisting of revision controlled files. These address list and files can be combined together to form a software release.

Some useful commands:

1. cvs checkout
2. cvs update
3. cvs add
4. cvs remove
5. cvs commit

7.  What is inode number in Linux?

Ans: An inode is a data structure on a usual Unix-style file system such as UFS or ext3. An inode stores fundamental information about a regular file, directory, or other file system object.  iNode number also called as index number.

8.  What is a zombie?

Ans: Zombie processes can be recognized in the output of ‘ps’ by the presence of ‘Z’ in the STAT column. Zombies are child processes whose parent process died without reaping its children. Zombies can’t be killed with the usual KILL signal. 

9.  Explain about MX record?

Ans: MX record numerically ranks the mail servers you would choose to receive email for a domain. The MX record with the lowest number is chosen over the others, but you can set multiple email servers with the same value for simple load balancing.

10. Define TCP hand shake?

Ans: TCP requires three packets to set up a socket connection, before any user data can be sent. This is called the tree way TCP handshake. First the requester sends a SYN packet and expects a SYN-ACK packet, to which the initiator replies with ACK packet plus the first chunk of user data.