Wednesday, April 11, 2012

Linux System Admin Interview Questions & Answers part 1

1. Every command in Linux is a

1. Text file
2. Stored variable
3. Executable program
4. None

 Answer: executable program

2. How long can a filename in Linux be?
Correct answer: 255 characters

3. What is the shortcut key to go to home directory?

1. shift + cd
2. cd + enter key
3. alt + ctrl + cd
4. ctrl + cd

Correct answer: cd

4. The hierarchy of a series of directories branching in a user home directory starts from?

Correct answer: /home

5. Saving open files, flush the system cache and other necessary system maintenance are allowed by.

1. Restarting the system
2. Rebooting the system
3. Logging off the system
4. Shutting down the system

Correct answer: logging off the system

6. Which directory contains configuration files that stores system and application setting?
1      /etc
2      /lib
3      /usr
4      /var

Correct answer: /etc

7. Which command is used to find data files, programs, directories that match the search argument?
Correct answer: locate

8. Applications written to provide a GUI shell for UNIX and Linux are called
Correct answer: x window

9. The advantage of using SAMBA rather than NFS for file sharing in Linux is?
Correct answer: compatibility with Windows file sharing

10. Which framework is provided for the programs to interchange information about Linux OS?

1. Resource Sharing Framework
2. Resource Security Framework
3. Information Sharing Framework
4. Resource Definition Framework

Correct answer: Resource Definition Framework

11. To implement new application on IBM z/10. Which of the following options need to be considered if it to be implemented in Linux?
Correct answer: Red Hat Linux does not support all the devices supported by IBM z/OS

12. Which of the following has greater market share of Linux SW/HW environment?
1. Linux on z10
2. Linux HP integrity servers
3. Linux on AS/400 servers locate
4. Linux on DELL Xeon

Correct answer: Linux HP integrity servers

13. Which of the following commands can be run to remove all the rules in an iptables table?
1. iptables -L
2. iptables -A
3. iptables -F
4. iptables –delete

Correct answer: iptables -F (F=Flush)

14. Which of the following is the BEST way to set up SSH(Secure Shell) for communicating between Systems without needing passwords?
1. Use ssh-keygen for generating public-private keys.
2. Disable passwords on specific accounts that will use SSH.
3. Both A and B
4. None of the above

Correct answer: Use ssh-keygen for generating public-private keys.

15. How much usable space is available, when a Linux system is configured with a RAID 5 array that consists of six 20 GB hard disk drives?
Correct answer: 100 GB

Formula: S*(N-1)
            here S=size
            N=number of HDD.  remember it is only for RAID5

16. Which of the following commands can be used to check for file corruption?

1. md5sum
2. checkfile
3. cat -vet
4. tar –checksum

Correct answer: md5sum

17. Which of the following allows to secure remote command line access?
Correct answer: SSH(Secure Shell)

18. Which of the following supports for creating a Linux VPN (Virtual Private Network)?
1. RC2
3. chap
4. NTLMv2

Correct answer: 3DES

19. Which of the following commands delete the files from the /tmp directory, issued by non-root user?
1.mdir -rf /tmp/*
2.rm -rf /tmp/* -su -c "rm -rf /tmp/*" "rm -rf /tmp/*"

Correct answer: su -c "rm -rf /tmp/*"

20. Which configuration does cardmgr read at Linux system startup?

1      PCMCIA     cards
2      PCI   cards
3      USB  cards
4      SCSI cards

Correct answer: PCMCIA cards

21. When a computer system is reported problems with inodes and blocks, which of the following are the problem and its solution to rectify it?

1. The file system has become corrupt and needs to be repaired.
2. The boot sector is corrupt and needs to be repaired.
3. The drive is configured using an improper file system and needs to be reformatted.
4. The partition table has become corrupt and needs to be replaced.

Correct answer: The file system has become corrupt and needs to be repaired. Use fsck command

22. Which Linux command will successfully mounts a USB drive?

1. mount /dev/uda1 /mnt/usb
2. mount /dev/sda1 /mnt/usb
3. mount -t usbfs /dev/usb001 /mnt/usb
4. mount /dev/hde1 /mnt/usb

Correct answer: mount /dev/sda1 /mnt/usb

23. ___________ is a common tool for determining services and ports running on a remote Linux.
1. arp
2. nmap
3. netstat
4. None of the above

Correct answer: nmap

24. For supporting new diskless client workstations, which of the following services needs to be installed on a server?

1      dhcpcd      and   rexec               
2      named       and   httpd                
3      remoted     and   dhcpd                       
4      PXE   (Preboot    eXecution   Environment)      and   tftpd

Correct answer: PXE (Preboot eXecution Environment) and tftpd

25. Which of the following Linux commands could be used to find what processor was detected on boot, when a laptop system is slow/
Correct answer: POST

26 . How to accomplish the LILO boot configuration updation for supporting a newly installed IDE hard drive?
Correct answer: Edit lilo.conf and run "lilo -v -v"



  1. Thanks for the post! I believe the answer to 15 is 100 however. S * (N-1) where 'S' is the size of the drives and 'N' is the number of disks in the array:

    20 * (6-1) = 100

  2. Hi Ben,

    Thanks for ur comment. you are correct. here we have total 6 HDD with 20Gb each. If it is configured with Hardware RAID, Total array size would be 100GB(RAID 5). but we can get approx. 93GB usable space. Array Controller will take some space and some space for cache.

  3. Hi,there. I believe the answer to question 8 should be X window, not windows.

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