4. Linux distributions

5. System overview

6. More detail: permissions, processes, package management, services

8. Free, open source software

9. Runs servers, desktops, phones, tablets, network equipment and more.

11. Number of distributions More than 350

12. Number of developers 1,000 developers contributed in 2010

13. Number of commits to linux kernel last year 195,579 commits in 2010

15. Different distributions have different target audiences

18. Debian / Ubuntu / Mint

21. Existing infrastructure

22. Admin experience

23. Support contract

24. Release supported lifetime

27. Originally based off of the Bourne Shell (sh)

28. Learn it, live it, love it

31. More extensive than the --help flag on CLI

34. Each user name and group name is linked to a number (UID/GID)

35. UID 0 = root

36. 0-99 typically used for system/service accounts

41. PPID: Parent PID

42. UID & EUID: real & effective user ID

43. GID & EGID: real & effective group ID

44. Niceness

45. Control terminal

47. Sent to terminal driver to kill, interrupt, or suspend

48. Sent by admin to kill

51. KILL & STOP – cannot be blocked

52. WINCH – term emulators

54. differ between UNIX's

55. show PID, UID, priority, control term, memory, status, etc

56. complex over the years, archaic

57. pstree

59. refreshes every 2-3 seconds

60. kill, renice, sort, memory, etc.