RHCSA Rapid Track

Log into your desktopX system as student, then elevate your privileges to root.

1. [student@desktopX ~]$ su -
   Password: redhat

Create a new daily cron job that logs a message to the system log with the number of currently active users (w -h | wc -l). You can use the logger command to send messages to the system log.

1. Open a new file in /etc/cron.daily in an editor, e.g., /etc/cron.daily/usercount.

   [root@desktopX ~]# vim /etc/cron.daily/usercount

2. Write the script that logs the number of active users to the system log.

   Insert the following in your editor:

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

3. Make the script executable:

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

The sysstat package, when installed, has a cron job that runs every 10 minutes, collecting data using a command called sa1. Make sure this package is installed, then change this job to run every five minutes.

1. Make sure the sysstat package is installed.

   [root@desktopX ~]# yum -y install sysstat

2. Find out in which file the sysstat package has configured the cron jobs. Cron jobs are generally configured in files marked as a configuration file for the package manager.

   [root@desktopX ~]# rpm -qc sysstat

   /etc/cron.d/sysstat looks promising.

3. Open /etc/cron.d/sysstat in an editor.

   [root@desktopX ~]# vim /etc/cron.d/sysstat

4. Change */10 on the sa1 line to */5.

5. Save your changes and exit.

6. Monitor the files in /var/log/sa to see when their sizes and timestamps change.

   [root@desktopX ~]# watch ls -l /var/log/sa