Operating Systems

Filesystem Manipulation & Permissions

Your Task

Locate and utilize linux system administration commands to create users and groups. Standard linux commands will be used to allocate specific user and group permissions for files and directories.

For admin tasks you will need to switch to the root user:

Part 1: User and Group Creation

“sudo su -“

Create 3 new groups:

cs

math

science

Create 2 new users named “steve” and “lucy” with the following attributes:

• default shell is /bin/bash
• comment (GECOS) field contains full names (Steve Smith / Lucy Goosey)
• steve primary group = math additional group = science
• lucy primary group = cs additional group = science

Make your own account members of all three groups.

Part 2: Create New Filesystems

Like we did last week, add 1 new 50 MB Fixed Size Virtual Disk to your linux Partition. This is done using the Virtual Box interface while your Linux Virtual Machine is shut down.

Using fdisk create 3 new 15 MB “linux” partitions on this newly added virtual disk.

Using mkfs.ext4, create 3 new filesystems on each new logical partition and mount them with the names below:

/math

/cs

/science

Once your filesystems are created and mounted, add an entry for each one in the /etc/fstab file in the corret format such that they automatically mount up when you reboot. Use UUID for the device so that the filesystem mounts even if the device address changes. Test and verify it is working by rebooting.

Part 3: Permissions

• Set group owner of /cs to “cs”
• Set group owner of /math to “math”
• Set group owner of /science to “science”
• Create a directry in /cs called cs_homework
• Create a directory in /math called math_homework
• Create a directory in /science called science_homework
• Adjust permission so only the owner and members of the group “cs” can access the “cs” filesystem
• Adjust permission so only members of the group “math” can access the “math” filesystem
• Adjust permission so anyone can access the “science” filesystem.

Note: you can use the “touch” command to create an empty file for testing. i.e. touch file1

• Create a file in /cs/cs_homework which only lucy can access with read only access.
• Create a file in /cs/cs_homnework which all members of cs group can access with read only access.
• Create a file in /math/math_homework which only steve can access with read and execute access.
• Create a file in /math/math_homework which all members of group math can access with read and execute access.
• Create a file in /science/science_homework which both steve and lucy can access with read and execute.
• Create a file in /science/science_homework which only steve can access with read / write / execute access.
• Create a file in /science/science_homework which only lucy can access with read / write / execute access.
• Create a file in /science/science_homework which anyone can access with read / write / execute permissions.

Use the long listing command to show filesytem, directory, and file permissions and capture screenshots.

Using the “df” commands, report how much space total space is allocated to each filesystem and how much is used. Report how many inodes are allocated and how many are used.

Submission Requirements

You will submit a Word or Libre Writer Document which contains results from the above analysis and responses. I do not have access to your system so you need to be sure to provide screenshots for anything I cannot possibly know. Only provide screenshots necessary to prove your responses.

Please insert your screenshots into your word document with supporting documentation which meets all requirements. You will be penalized for any results which are not backed by proof.