Need help in a aspect of Linux System administration I am r.pdf
- 1. Need help in a aspect of Linux System administration. I am required to address Linux administration problems Linux administration problems via executing appropriate system commands or via editing / modifying appropriate system files. The solutions must be for RedHat7.x/CentOS7.x and higher version to be marked properly by automatic marking system. My solution will have to be uploaded in a single TEXT (26 line) file, each line of the file being answer / solution to the task / question specified. Each line has to start with the task number followed by system command (for the solutions requiring executing system commands) or line you would enter into shell / appropriate configuration file content (for the solutions requiring modification of appropriate system files) to achieve requested result. For example, if task 3 was to provide command configuring network interface eth0 so that the IP address was 192.168.0.2, network mask was 255.255.255.128 and the broadcast address was 192.168.0.255, you would enter the line as: 3. ifconfig eth0 192.168.0.2 netmask 255.255.255.128 broadcast 192.168.0.255 These are the 26 questions : Thanks for the help in advance! 1. Which file you would use to redefine existing system variable PATH (provide full path)? 2. How would you redefine the PATH variable to add path to /home/john/bin directory? 3. Which file you would use to limit maximum number of logins for a user mariusz to 3 logins at a time (provide full path)? 4. How would you modify the above file to achieve the result (please show how the line you would add to the file would look like)? 5. You were requested to add to the system new user called tatiana. You want to execute the command adding the user to the system so that default shell for tatiana was be /bin/sh and her initial / primary group was students. How would the command look like? 6. One of the system users asked you to change his login name from pm75 to mariusz. How would you achieve this (provide appropriate command)?7. You want to add user mariusz to ACL (Access Control List) of file /usr/share/ccsm so that this use had read permission (assume the user does NOT belong to the file group nor he is the file owner). 8. You want to change current permissions for file /usr/share/ccsm to rwxrr. How the command allowing you to achieve the goal would look like. 9. You want to check your file system supports ACL. Which command would tell you this? 10. You want to create in the current directory symbolic link ptr to file /usr/share/ccsm. How the command allowing you to achieve this would look like? 11. One of the system users clare forgot her password. How the command initialising her password change would look like? Assume you execute the command as root (in other words: what command would root execute to change clare's password). 12. Which file you would modify to add a new DNS server (provide full path)? 13. How would the entry (line) to the above file look like if the DNS server you wanted add to the system was 217.173.13.13? 14. You want to execute /usr/share/ccsm script every Sunday at 2pm . How the crontab entry allowing you to achieve this would look like? 15. As system admin (root) you copied /usr/share/ccsm file to the home directory of user ben. Assuming user ben has his home directory in the default location for CentOS7.x system, show how you would make the file to be owned by ben and belong to system group students? 16. You want immediately lock account for student ben (so that he was unable to login to the system) as it turned out he has fee hold status. How the command allowing you to achieve this would look like? 17. You want to check
- 2. which process(es) running in the system is / are owned by user ben. How the command allowing you to achieve this may look like? 18. Suppose you have just finished a completely fresh Linux installation. However, after first system boot it turned out that it by default takes you to the graphical user interface login prompt (meaning the system boots by default into graphical.target). Which command would list you all targets to choose from as an alternative to the graphical.target? (provide full command)? 19. How you would change the default target to multiuser.target which allows multi user mode but with the graphical user interface not starting (provide full command)? 20. You want to change default location for the users' home directory from/home to /home/users. Which file you would use to make it a default setting (provide full path)? 21. How the entry (line) to the above file would look like. 22. Assuming that your network interface name is enp0s 3 , you would like change default settings for this interface to enforce it to request IP address from a DHCP server. Which file you would use to force this (provide full path)? 23. How the entry (line) in the above file would look like? 24. As normal / standard Linux system user mariusz you spotted that you r default shell is Korn shell /bin/ksh. You definitely prefer BASH /bin/bash shell over Korn shell (/bin/ksh) so you want it to get changed permanently. However, you do not want to engage system admin to achieve this as you are perfectly capable to do it on your own. Which file you would modify (provide full path assuming default location for the user's home directory)? 25. How the line allowing you to change your default shell would look like. 26. How would you interpret Heisenberg Uncertainty Principle in the context of wavelet analysis?