linux interview questions and answers

Linux Administration
For more details :- http://raju-linux-admin.blogspot.in
Interview Questions and Answers
What is Linux
Linux is, in simplest terms, an operating system. It is the
software on a computer that enables applications and the
computer operator to access the devices on the computer to
perform desired functions
What is LILO?
LILO stands for Linux Loader. LILO is Linux's boot loader
which is used to boot up Linux. It can also be used to dual-boot
or multi-boot different operating systems.
INSTALLATION
Which account is created when you install Linux?
Super user account or the root user account

KERNEL
What is kernel ?
The core of the Linux system is the kernel. The kernel controls
all of the hardware and software on the computer system,
allocating hardware when necessary, and executing software
when required.
What is Netfilter?
The Linux kernel’s network packet processing subsystem is called
Netfilter
What is notification chains?
The kernel’s many subsystems are heavily interdependent, so an
event detected or generated by one of them could be of interest to
others. To fulfill the need for interaction, Linux uses so-called
notification chains

LVM
What do you mean by LVM?
Logical Volume Manager(LVM ) allows administrators the
flexibility to create logical disks that can be expanded
dynamically as more disk space is required
How to see the logical volume and its sizes?
# lvs
How to remove the LVM?
# umount /dev/vg_name/lv_name
# lvremove /dev/vg_name/lv_name

PARTED
How can you display the information about disk drive?
# parted
How can you l check free space on drive /dev/sda with
parted
command?
#parted /dev/sda
What is the use of parted command?
Add the partition
View and change the existing partition

FILE SYSTEM
and the RAM is full, inactive pages in memory are moved to the swap space.
Which partition is used for virtual memory by a Linux system?
swap
How to check the swap space?
free -m
What you mean by linux filesystem?
The file system is divided into many parts; the filesystem with /bin , /lib ,
/etc , /dev , and a few others; a /usr file system with programs and
unchanging data; /var filesystem with changing data
How to identified the files accessed within 25 days?
# find / -type f -atime -25 > file_name.files
How to find out which file system running on your linux server
currently?
# df

USER & SECURITY
swap
free -m
What is user?
Linux is provided by users and groups. Each user is associated with a
unique positive integer called the user ID (uid). During login, the user
provides a username and password to the login program
How to create a user?
# adduser user_name
# useradd user_name
How to set to expire the particular user account?
# chage -E 30/12/2016 user_name

DNS
swap
free -m
What is DNS?
Domain N ame System (DN S) is the system that associates
hostnames with IP addresses
What does BIND Stands for ?
BIND stands for Berkeley Internet Name Domain
What is the role of DNS ?
A DNS server, or name server, is used to resolve an IP address to
a hostname

TCP / IP NETWORKING
swap
free -m
What is TCP?
TCP is a connection - oriented communication protocol. It maintains
the state of the connection at any given point of time
What is IP header?
The IP header has fixed as well as optional fields. The fixed header
is 20 bytes long and the rest is optional
How the packet filtered within the ipchain?
Ip chains filter incoming, outgoing, and the forwarded packets

IPTABLES & FIREWALL
swap
free -m
What Is Firewall?
A firewall is a hardened and trusted host that acts as a choke
point among a group of networks
What is iptables?
Iptables is a generic table structure that defines rules and commands
as part of the netfilter framework that facilitates Network Address
Translation (NAT), packet filtering, and packet mangling in the Linux
What Is IP Filtering?
IP filtering is simply a mechanism that decides which types of IP
packets will be processed normally and which will be dropped or
rejected

RAID
swap
free -m
What is RAID?
RAID means Redundant Array of Independent Disks configuration to
further protect against multiple failures
Does Linux Support Virtualized File Systems Like RAID?
The most recent Linux kernels support software RAID, and they will work
with RAID disk controllers
What is software RAID?
Software RAID means that an array is managed by the kernel, rather
than by specialized hardware

BACKUP & RECOVERY
swap
free -m
What is backup?
Backing up, refers to the copying and archiving of computer data so it
may be used to restore the original after a loss event
Why we need backup?
Backups are needed in case a file or a group of files is lost. The reasons
for losing files include . Hardware failure like disk breaking, accidentally
deleting wrong file and computer being stolen. Backups help in all the
above situations.
What is simple backup?
The simplest means of making a backup is to use tar to archive all the
files on the system or only those files in a set of specific directories

VCS
swap
free -m
What you mean by VCS?
Veritas Cluster Server also known as VCS is a High-availability
cluster software, for Unix, Linux and Microsoft Windows computer
systems
What is the use of VCS Simulator?
VCS Simulator enables you to simulate and test cluster configurations.
Use VCS Simulator to view and modify service group and resource
configurations and test failover behavior.
How to check the status of VCS?
# hastatus –summ

APACHE
What is apache server?
The Apache HTTP Server, colloquially called Apache is the world's
most used web server software
How to check the version of Apache server ?
rpm -qa |grep httpd
What is the main configuration file for Apache?
httpd.conf

RPM
What is ftp?
The File Transfer Protocol (FTP) is a standard network
protocol used to transfer computer files from one host to
another host over a TCP-based network, such as
the Internet.
What does vsftpd stands for?
Vsftpd means very secure FTP daemon
What all are the default port for vsftpd server?
Port numbers 20 & 21

SAMBA
What is Samba?
Samba is a suite of Unix applications that speak the SMB
(Server Message Block) protocol. Many operating systems
What is SWAT?
Samba Web Administration Tool (SWAT) is used to simplify
administration and configuration of Samba
How to install samba?
# yum -y install samba

linux interview questions and answers

More Related Content

What's hot

Viewers also liked

Similar to linux interview questions and answers

Recently uploaded

linux interview questions and answers