Linux admin Interview Questions

Linux admin Interview Questions

1.What is difference between Hard Link and Soft Link?

ANS: In Hard Link a new hard link is created to reference the same file. Means new file is created which point to the same reference file. And in Soft Link a link is created like as a shortcut. 

2.Can we change port number of ssh. If yes, then to how?

ANS: Yes, we can change port number of ssh. Default port number of ssh is 22. To change port number of ssh from 22 to 2222 there have a need to configure following file.

vim /etc/ssh/sshd_config

In above file search the line that specifies the port number. Remove # sign before that line. Insert number 2222 with replace to 22. Then reload the firewall and restart the sshd service.

3.What is default permission of file and directory?

ANS: File default permission is 664

          Directory default permission is 775

4.What is difference between YUM and RPM?
ANS: YUM is a Yellowdog Update Manager which is used to resolve dependencies.
 RPM does not resolve dependencies.

5.What is LVM? Why LVM is used?
ANS: Learn LVM in more details

6.What is difference between ps and Top command.
ANS: Both Top and ps commands are used to see status of processes. Top command shows dynamic view of systems processes. In Top command processes continuously refreshes at a configurable interval. ps command shows static view of processes, which are not refreshes at a interval.