linux interview question and answer for fresher 3

What is ‘inode’?

All UNIX files have its description stored in a structure called ‘inode’. The inode contains info about the file-size, its location, time of last access, time of last modification, permission and so on. Directories are also represented as files and have an associated inode.

Tell me the steps to remove the swap file?

Firstly disable the swap file by “swapoff” command.
Remove Swap file entry from /etc/fstab file.
Now remove the swap file by “rm” command.

What is LVM?

LVM stands for Logical Volume Manager. LVM, is a storage management solution that allows administrators to divide hard drive space into physical volumes (PV), which can then be combined into logical volume groups (VG), which are then divided into logical volumes (LV) on which the filesystem and mount point are created.

What are the steps to create LVM?

- Create physical volumes by “pvcreate” command
#pvcreate /dev/sda2

- Add physical volume to volume group by “vgcreate” command
#vgcreate VLG0 /dev/sda2

- Create logical volume from volume group by “lvcreate” command.
#lvcreate -L 1G -n LVM1 VLG0

Now create file system on /dev/sda2 partition by “mke2fs” command.
#mke2fs -j /dev/VLG0/LVM1

 How we will check free space on drive /dev/sda with parted command?

#parted /dev/sda
print

What are the process states in Unix?

As a process executes it changes state according to its circumstances. Unix processes have the following states:

Running : The process is either running or it is ready to run .
Waiting : The process is waiting for an event or for a resource.
Stopped : The process has been stopped, usually by receiving a signal.
Zombie : The process is dead but have not been removed from the process table.

What is the difference between LVM and RAID?

RAID provides redundancy but LVM doesn’t provide Redundancy.

What is physical extent (PE)?

Each physical volume is divided chunks of data, known as physical extents; these extents have the same size as the logical extents for the volume group.

What command is used to remove the password assigned to a group?

gpasswd –r

What is the basic difference between UNIX and Linux Operating System?

 Linux Operating System is Free and Open Source Software, the kernel of which is created by Linus Torvalds and community. Well you can not say UNIX Operating System doesn’t comes under the category of Free and Open Source Software, BSD, is a variant of UNIX which comes under the category of FOSS. Moreover Big companies like Apple, IBM, Oracle, HP, etc. are contributing to UNIX Kernel.

Linux is which kind of Operating System?

Linux is an Operating System which supports MultiUser, Running a Number of Processes performing different tasks simultaneously.

What the command used for Search file or files for specific text?

grep command used for files for specific text.

How to create a folder in linux?

mkdir <directory name>
Create new folder or directory, if they do not already exist already
syntex like below
mkdir [Options] directories
OPTIONS
-m, --mode=MODE set permission mode (as in chmod), not rwxrwxrwx - umask
-p, --parents no error if existing, make parent folder as needed 

mkdir creates the standard entries . (dot) for the current folder and .. (dot dot) for its parent.

How you will check on Your server or system device-mapper is installed or not?

Check the following file.
#cat /proc/misc

if this file contains “device-mapper” term it means device mapper is installed on your system.