Assignment # 3

Users and Filesystems

Part 1 : User Management

You are a Systems Administrator at NASA's Kennedy Space Center. You have just installed a new Linux , Solaris and NT machine and must create a number of user accounts for the different types of people that will be working with all three machines:

1. Create five accounts (with passwords) for the following people:

   Frank Booster (astronaut)

   Susan Weightless (astronaut)

   Rodney Wrench (ground crew engineer)

   Larry Launchalot (mission director)

   Lance Leadfoot (ground crew driver)

2. Create three groups, one for the astronauts, one for the ground crew, and one for the mission director. Add the above users into the following groups:

Astronauts: Frank Booster, Susan Weightless

Ground Crew: Rodney Wrench, Larry Launchalot, Lance Leadfoot

Director: Larry Launchalot

3. Set up their accounts so each has a private home directory that only the individual account has read, write, and search access to.
4. Set up directories where each of the groups has read/write/search & execute permission. In other words, create a directory somewhere on your machine for each of the three groups that only members of that group can read/write/execute (all other users have no access). Under NT, make sure you include the appropriate other access rights for the group (all but Full Control).
5. Use appropriate naming conventions for each of the operating systems. The names should be as close as possible to the names given in the assignment (or easily recognized if abbreviations are required).

Information on creating users and accounts can be found in Chapter 5 of ESA (especially the writeups on useradd and admintool) and in Chapter 3 of EWNTSA.

Deliverables

To prove you performed these steps, include a writeup of the steps that you went through to create these accounts and groups in your submitted journals.

Include in the writeup tests performed by each of your new users that show correct file permissions for individuals and groups. For instance, under the UNIX-based operating systems, you could show the output of a shell session under the user you created for Larry Launchalot. It would include a series of "touch" and "ls" commands that indicate Launchalot is permitted to create files in his own home directory as well as in the Ground Crew and Director directories, but NOT the Astronauts directory. Include the relevant portions of affected system files (the new lines you added to /etc/passwd and /etc/group, for instance).

A useful tool for recording session information on Unix is "script". It can be easier than manual transcription or Xwindows copying & pasting. See "man script" for details. Please edit the output so I do not have to grade very large text files!

Part 2 : Experimenting with UNIX Filesystems

Perform the following steps on both your Linux and Solaris machines. Keep a diary or a "script" transcript for your writeup:

1. Create a local file system on a 3 & 1/2 inch floppy, using the correct device name for a 1.44MB density floppy.

   (Hints: "fdformat", "mkfs", "newfs", "man fd", "man -s 7d fd")

2. Verify the filesystem is OK and mount the filesystem. Copy a portion of your UNIX tree to it.

   (Hints: "fsck", "mount").

   • A useful way of copying a portion of a UNIX tree is by using a "tar" pipe. Assuming you have mounted your floppy filesystem on /mnt, this would copy all the files and subdirectories from "/etc" onto your floppy (beware that the contents of /etc may be larger than space available on your floppy):

       cd /
       tar cf - etc | (cd /mnt; tar xpf - )
     

3. Unmount the filesystem and re-fsck it ("umount", "fsck").
4. Mount the filesystem again.
5. Remove the floppy from the floppy drive (leave the file system mounted!).
6. Attempt to perform some I/O on your mounted filesystem (like attempting an "ls -lR"). Record what you see and explain what is happening.
7. Unmount the filesystem. Record what you see and explain what is happening.
8. Re-insert the floppy drive and make sure the filesystem is OK. Show the steps you had to go through to get things back in sync (pun intended :).
9. Add a line to the appropriate startup file on Linux and Solaris so that your floppy-based filesystem is mounted at boot time.
10. Reboot your machine and verify that the floppy mounts and the files on the floppy are accessible.
11. Remove the floppy from the drive and reboot. What happens when a required file system is not available? What can you do to get around the problem?
12. Remove the entry for the file system on the floppy from the file you edited earlier so it is no longer a required filesystem.
13. Answer the following questions:
    • Are floppy-based filesystems for Solaris and Linux interchangeable? Can you mount, say, the Solaris floppy on Linux and vice versa?
    • Can you store the same amount of data on both floppy-based filesystems or can one hold more than the other?
    • Is there a difference in the way both operating systems behave when a required filesystem is missing?
    • Is there a difference in the way both operating systems behave when a filesystem "disappears" out from underneath a mount point?