Red Hat System Administration I

Log in to serverb as the student user.

[student@workstation ~]$ ssh student@serverb
...output omitted...
[student@serverb ~]$

Identify and terminate the process that currently uses the most CPU time.

1. Use the top command to view the real-time system CPU consumption.

   [student@serverb ~]$ top

2. From the interactive interface of the top command, look at the %CPU column and confirm that a dd process is consuming the most CPU resources.

   ...output omitted...
   PID USER      PR  NI    VIRT    RES    SHR S  %CPU  %MEM     TIME+ COMMAND
   2303 student   20   0  217048    944    876 R  99.7   0.1 100:11.64 dd
   ...output omitted...

   The dd process in the preceding output has the 2303 PID. This process is consuming 99.7% of the CPU resources. The PID and the percentage of CPU resource consumption would vary in your system.

3. From the interactive interface of the top command, type k to kill the dd process with the 2303 PID, as you determined in the preceding step. After you type k in the top command, if the default PID that is shown in the prompt matches the PID of the process to terminate, then press the Enter key. If the suggested PID does not match, then specify the PID interactively.

   ...output omitted...
   PID to signal/kill [default pid = 2303] Enter
   ...output omitted...

4. Use the default SIGTERM signal to terminate the process.

   ...output omitted...
   Send pid 2833 signal [15/sigterm] Enter
   ...output omitted...

5. Press the q key to quit the interactive interface of the top command.

Create the database group with a GID of 50000.

1. Switch to the root user.

   [student@serverb ~]$ sudo -i
   [sudo] password for student: student
   [root@serverb ~]#

2. Create the database group with a GID of 50000.

   [root@serverb ~]# groupadd -g 50000 database

Create the dbadmin1 user. Add the database group as a supplementary group. Set the password to redhat and force a password change on the user's first login. Allow the password to change after 10 days since the day of the last password change. Set the password expiration to 30 days since the day of the last password change. Allow the user to use the sudo command to run any command as the superuser. Configure the default umask as 007.

1. Create the dbadmin1 user. Add the database group as a supplementary group.

   [root@serverb ~]# useradd -G database dbadmin1

2. Set the password of the dbadmin1 user to redhat.

   [root@serverb ~]# passwd dbadmin1
   Changing password for user dbadmin1.
   New password: redhat
   BAD PASSWORD: The password is shorter than 8 characters
   Retype new password: redhat
   passwd: all authentication tokens updated successfully.

3. Force the dbadmin1 user to change its password on the next login.

   [root@serverb ~]# chage -d 0 dbadmin1

4. Set the password's minimum age of the dbadmin1 user to 10 days.

   [root@serverb ~]# chage -m 10 dbadmin1

5. Set the password's maximum age of the dbadmin1 user to 30 days.

   [root@serverb ~]# chage -M 30 dbadmin1

6. Enable the dbadmin1 user to use the sudo command to run any command as the superuser. Use the vim /etc/sudoers.d/dbadmin1 command to create the file and add the following content:

   [root@serverb ~]# vim /etc/sudoers.d/dbadmin1
   dbadmin1 ALL=(ALL) ALL

7. Switch to the dbadmin1 user. Append the umask 007 line to the /home/dbadmin1/.bashrc file.

   [root@serverb ~]# su - dbadmin1
   [dbadmin1@serverb ~]$ echo "umask 007" >> .bashrc

8. Source the ~/.bashrc file to update the umask.

   [dbadmin1@serverb ~]$ source ~/.bashrc

Create the /home/dbadmin1/grading/review2 directory with dbadmin1 as the owning user and the database group as the owning group.

1. Use the mkdir command -p option to create the /home/dbadmin1/grading/review2 directory.

   [dbadmin1@serverb ~]$ mkdir -p /home/dbadmin1/grading/review2

2. Recursively set dbadmin1 and database as the respective owning user and group of the /home/dbadmin1/ directory and subdirectories.

   [dbadmin1@serverb ~]$ chown -R dbadmin1:database /home/dbadmin1/

3. Recursively set group execute permissions on the /home/dbadmin1 directory and subdirectories. This permission allow members of the database group to traverse the /home/dbadmin1 directory structure.

   [dbadmin1@serverb ~]$ chmod -R g+x /home/dbadmin1

Configure the /home/dbadmin1/grading/review2 directory to allow members of the database group to create contents in it. All other users should have read and execute permissions on the directory.

1. Apply the SetGID special permission on the /home/dbadmin1/grading/review2 directory so that the database group owns files that are created in the directory.

   [dbadmin1@serverb ~]$ chmod g+s /home/dbadmin1/grading/review2

2. Apply the 775 permission mode on the /home/dbadmin1/grading/review2 directory.

   [dbadmin1@serverb ~]$ chmod 775 /home/dbadmin1/grading/review2

Ensure that users are allowed to delete only files that they own from the /home/dbadmin1/grading/review2 directory.

1. Apply the sticky bit special permission on the /home/dbadmin1/grading/review2 directory.

   [dbadmin1@serverb ~]$ chmod o+t /home/dbadmin1/grading/review2

2. Return to the workstation system as the student user.

   [dbadmin1@serverb ~]$ exit
   logout
   [root@serverb ~]# exit
   logout
   [student@serverb ~]$ exit
   logout
   Connection to serverb closed.