Unix Administrator Interview Questions

Unix & Linux admin questions

  1. How do you list the files in an UNIX directory while also showing hidden files?
  2. How do you execute a UNIX command in the background?
  3. What UNIX command will control the default file permissions when files are created?
  4. Explain the read, write, and execute permissions on a UNIX directory.
  5. What is the difference between a soft link and a hard link?
  6. Give the command to display space usage on the UNIX file system.
  7. Explain iostat, vmstat and netstat.
  8. How would you change all occurrences of a value using VI?
  9. Give two UNIX kernel parameters that effect an Oracle install
  10. Briefly, how do you install Oracle software on UNIX.
  11. What are the main differences between Apache 1.x and 2.x?
  12. What does the “route” command do?
  13. What are the read/write/execute bits on a directory mean?
  14. What does iostat do?
  15. what does vmstat do?
  16. What does netstat do?
  17. What is the most graceful way to bring a system into single user mode?
  18. How do you determine disk usage?
  19. What is AWK?
  20. What is SED?
  21. What is the difference between binaries in /bin, and /usr/bin?
  22. What is a dynamically linked file?
  23. What is a statically linked file?
  24. How do you list the files in an UNIX directory while also showing hidden files? ls -ltra
  25. How do you execute a UNIX command in the background? Use the “&”.
  26. What UNIX command will control the default file permissions when files are created? umask
  27. Explain the read, write, and execute permissions on a UNIX directory. Read allows you to see and list the directory contents. Write allows you to create, edit and delete files and subdirectories in the directory. Execute gives you the permissions to run programs or shells from the directory.
  28. What is the difference between a soft link and a hard link? A symbolic (soft) linked file and the targeted file can be located on the same or different file system while for a hard link they must be located on the same file system.
  29. Give the command to display space usage on the UNIX file system. df -lk
  30. Explain iostat, vmstat and netstat. iostat reports on terminal, disk and tape I/O activity. vmstat reports on virtual memory statistics for processes, disk, tape and CPU activity. netstat reports on the contents of network data structures.
  31. How would you change all occurrences of a value using VI? %s/(old value)/(new value)/g
  32. Give two UNIX kernel parameters that effect an Oracle install. SHMMAX & SHMMNI
  33. Briefly, how do you install Oracle software on UNIX? Basically, set up disks, kernel parameters, and run orainst.
  34. Job Scheduling; mainly crontab, at, batch command
  35. Backup stetegy; incremental, full system back up; diff between tar & ufsdump
  36. diff between hard link & softlink
  37. How to list only the directories inside a directory (Ans. ls -l|grep "^d")
  38. RAID levels; pros & cons of diffrent levels; what is RAID 1+0
  39. How to recover a system whose root password has lost?
  40. What is a daemon?
  41. How to put a job in background & bring it to foreground?
  42. What is default permissions for others in a file?
  43. Questions on shell initialization scripts?
  44. Questions on restricted shell
  45. What is diff betwn grep & find?
  46. What is egrep?
  47. Questions on shell programming
  48. What is a pipe?
  49. Questions on Solaris patch management like pkgadd etc
  50. Questions on file system creation; actually what happens when we create a file system?
  51. Questions on RBAC? what is a role accound & what is a profile?
  52. From command line how will you add a user account? the full command will all arguments.
  53. Fs it advisable to put a swap partion in RAID1 (mirroring?) pros & cons?
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