RHCSA Rapid Track

Instructions

1. Log in to the servera machine as the student user and switch to the root user.

   [student@workstation ~]$ ssh student@servera
   ...output omitted...
   [student@servera ~]$ sudo -i
   [sudo] password for student: student
   [root@servera ~]#

2. Schedule a recurring system job that generates a log message to indicate the number of active users in the system. This job must run daily and use the w -h | wc -l command to retrieve the number of active users in the system. Use the logger command to generate the log message of currently active users.

   1. Create the /etc/cron.daily/usercount script file with the following content:

      #!/bin/bash
      USERCOUNT=$(w -h | wc -l)
      logger "There are currently ${USERCOUNT} active users"

   2. Make the script file executable.

      [root@servera ~]# chmod +x /etc/cron.daily/usercount

3. Install the sysstat package. The timer unit must trigger the service unit every ten minutes to collect system activity data with the /usr/lib64/sa/sa1 shell script. Change the timer unit configuration file to collect the system activity data every two minutes.

   1. Install the sysstat package.

      [root@servera ~]# dnf install sysstat
      ...output omitted...
      Is this ok [y/N]: y
      ...output omitted...
      Complete!

   2. Copy the /usr/lib/systemd/system/sysstat-collect.timer file to the /etc/systemd/system/sysstat-collect.timer file.

      [root@servera ~]# cp /usr/lib/systemd/system/sysstat-collect.timer \
      /etc/systemd/system/sysstat-collect.timer

   3. Edit the /etc/systemd/system/sysstat-collect.timer file for the timer unit to run every two minutes. Replace any occurrence of the 10 minutes string with 2 minutes throughout the unit configuration file, including the occurrences in the commented lines. Use the vim /etc/systemd/system/sysstat-collect.timer command to edit the configuration file.

      From these changes, the sysstat-collect.timer unit triggers the sysstat-collect.service unit every two minutes, and collects the system activity data in a binary file in the /var/log/sa directory.

      ...output omitted...
      # Activates activity collector every 2 minutes
      
      [Unit]
      Description=Run system activity accounting tool every 2 minutes
      
      [Timer]
      OnCalendar=*:00/2
      
      [Install]
      WantedBy=sysstat.service

   4. Notify the systemd daemon of the changes.

      [root@servera ~]# systemctl daemon-reload

   5. Activate the sysstat-collect.timer unit.

      [root@servera ~]# systemctl enable --now sysstat-collect.timer
      ...output omitted...

   6. Wait until the binary file is created in the /var/log/sa directory.

      The while command, ls /var/log/sa | wc -l returns 0 when the file does not exist, or returns 1 when the file exists. The while command pauses for one second when the file is not present. The while loop exits when the file is present.

      [root@servera ~]# while [ $(ls /var/log/sa | wc -l) -eq 0 ];  \
      do sleep 1s; done

   7. Verify that the binary file in the /var/log/sa directory was modified within two minutes.

      [root@servera ~]# ls -l /var/log/sa
      total 4
      -rw-r--r--. 1 root root 2540 Apr  5 04:08 sa05
      [root@servera ~]# date
      Tue Apr  5 04:08:29 AM EDT 2022

   8. Return to the workstation machine as the student user.

      [root@servera ~]# exit
      logout
      [student@servera ~]$ exit
      logout
      Connection to servera closed.
      [student@workstation ~]$