Linux Important Questions

Below Question is very useful for Interviews,if you know the Answer mention in comment with question  and number.

1. What is a Linux ?

2. What is a Linux Distribution ?

3. why Linux is Secured ?

4. How BIOS Works ?

5. Location of MBR ?

6. What is a Link and types of Links in Linux ?

7. what is the use of ls command ?

8.  How to check which run level are running the system ?

9. what is the use of init3 ?

10. why X11 ?

11. how to set default run level, why run level 4 is unused and still there ?

12. what is N in run level ?

13. what is the  use of Swap space,if Swap space not given what happen ?

14. What is the use of Journaling ?

15. what is the difference between / and /root ?

16. How Daemon Process Works ?

17. How to Delete the file inside the sub directories ?

18. How to create user in linux ?

19. Which command not shown in MAN (help)?
Ans: $Man tracert

20. Swap space is compulsary in partition or not ?

21. Difference between whoami and who am i ?

22. Difference Between Locate and Slocate ?

23. Difference Between grep and AWK  ?

24. Defference Between Hard and Soft link ?

25. What is the use of Nice and Renice ?

26. Which process Start the after the file system 
Ans : INIT

27. Explain TOP Command,columns and rows ?

28. How to Check Top 10 users are using system usage ?

29.How to Kill particular user ?

30. What is the use of Fstab and fsck ?

31. How to check the access time,modify time of the file ?
Ans: stat filename 

32. How to Check Userid and Group ID of the user ?
Ans: $cat /etc/login.defs

33. How to check the  which bit or using like 32 or 64bit ?
ans: $getconf LONG_BIT

34. How to create a user Manual in Linux ?
Ans : Update the user information
          /etc/passwd
          /etc/shadow
          /etc/group
          /etc/skel

35. Default Permission of the Directory in Root and Normal User?
Ans : Root : 755  ( umask :022 )
         Normal User : 775 ( Umask : 002 )

36. Default Permission of the File in root and Normal User ?
 Ans: Root               : 644  ( umask :022 )
         Normal User :  664 ( Umask : 002 )


37. What is a  Sticky Bit ?

38. How to Check hostname and Ip Address ?

39. How to change the Ip Address ?

40. What is the use of  this Commands Netstat,vmstat,iostat,sar ?

41. Difference Between RPM and YUM ?

42. How to to Send the file from one system to another system ?

43. What is the use of SSH  and Ping ?

44. What is the use of Crontab ?

45. How to Check free and used space in system ?

46. What is the use of Samba ?