Frequently Asked Linux Interview Questions

PART-1

1. How did you install Linux server on your machine.
2. How do you configure Linux Kick start installation?
3. What services do you require to share something?
4. NFS configuration, options……what do you know about root squash?
5. What protocols are used in NFS?
6. What are services are required for NFS share to mount on a client.
7. Tell me something about LVM. How would you know that system in LVM enabled.
8. How many Raids are you familiar with? Tell me in brief about RAID 1 & 5.
9. how do you find what RAID on the system in configured.
10. Tell me about some security aspects about NFS client share.
11. Have you heard about semaphore?
12. How would you know about NFS registered services on a machine?
13. What is port?
14. What are the differences between TCP & UDP?
15. In system where is 100% memory utilized, how would you check whether the system has performance issue or not? And what does it indicates to you when the system is showing 100% utilization.
16. What causes normally the load average to go up?
17. What are differences between module and kernel?
18. What is inter-process communication?

PART-2

19. What is your day to day activity in you current organization.
20. How can you recognize LUN in your Linux machine?
21. What is GRUB?
22. What is difference between regular and General file system
23. If generals are corrupted in your system, how would you recover them
24. What are differences among RPM, UP2DATE and YUM.
25. How will you set kernel parameter? Permanent/Temporary.
26. how do you check  open files in your system and which kernel parameter is used by kernel parameter.
27. How do you steup Printer in your system.
28. How would you check configured Printers in your system?
29. What is Sticky Bit and where is it by default set in your system
30. what does TOP command do and what parameter it contains for memory.
31. Have you worked on Backup Tool like VERITAS Netbackup.
32. How would you configure backup client on your system.
33. How would you judge system performance?
34. How would you check system load average?
35. How to know CPU is bottlenecked and CPU is HIGH and what remedies would you like to use to overcome this issue.
36. What is difference between real time and user process?
37. Tell me about iostat command and its parameter.
38. What will you give solution about HIGH I/O wait is your machine.
39. How can you design Hardware configuration (Dev/Test/Prod).
40. Why we use default gateway in your system.
41. Tell me some applications which use TCP/UDP protocols.
42. How will you troubleshoot if use is not able to login in Linux machine
43. How can you lock and unlock user in Linux.
44. What cluster services are used in Linux cluster?
45. How can you check commands run by last user.
46. How can you partition in Linux system at run time.
47. What is use of partprobe command in Linux?
48. How will you setup ssh pass-through.
49. What is usage of passphrase?
50. What is difference between grep and find.
51. How will you find out a particular string in a file by using grep and find.
52. What is usage of redirection operator (> & >>).
53. Shell Scripting----- $$, $! ,$@, $0,$?
54. How can you pass argument to script.

PART-3

55. How can you configure Linux virtual machine?
56. How can you check xen enabled kernel and OS?
57. What would be effect if grub not in OS.
58. How to upgrade kernel in Linux machine.
59. What is RPM and what are usage if –U and –F options with rpm command.
60. what are zombie processes and how can you detect them into your system
61. How can you kill zombie processes?
62. What is the usage of nslookup command?
63.  where can you set priority for resolving naming resolution in Linux machine.(nsswitch.conf)
64. How can you find out whether system is NIS enabled or not.
65. What is difference between CRON and AT.
66. What is swap and when we use it.
67. Command to check swap in your system.
68. What is daemon?
69.  What are the daemons used for logs in Linux.
70.  What is HARD and SOFT link and why we use them?
71. How to check inode in your sysem.
72. Why we use lsof.
73. What is superblock and inode
74. what is usage of modprob.conf.
75. How can load and unload modules in your system.
76. How can you share data through NFS.
77. What is PXE and how will you setup it.
78. What is subnet mask?
79. How can you boot Linux machine in single use mode.
80. How can you check the type of file system without mounting them?

PART-4

81. What is heartbeat
82. How can you reset group password.
83. How can you encrypt the group password.
84. How can you create script to run specific command on 1000 boxes.
85. Do you know about Veritas cluster?
86. How can you rename volume group.
87. What is difference between apache1.3 and apache2.0
88. How can you compile the kernel?
89. How can you reload NFS configuration file without restating services.
90. How can you temporary share NFS without making entry into /etc/exports?
91. What is multipath and how can you configure it for different Storage.
92. What is bonding and what is use of it.
93. How can you check the file system?
94. How will you extend and reduce LVM.
95.  What is NFS Stale?
96. How will you troubleshoot if kernel is panic after up gradation?
97. What is ARP and what is its use.
98. What are major and minor numbers?
99. Tell me about different type of files in Linux and give some example of block and character devices.

100.    How can you change nice value of process?