Troubleshooting and System Maintenance: RHCE Components

You have to solve three of the five simulated RHCE-level problems correctly. Your time starts after you've answered all of the simulated RHCT problems correctly; thus, you'll have at least 1.5 hours for this part of the exam. Ideally, you'll have a friend or classmate help you prepare your computer. Assume that you have access to a network server with the RHEL installation files.

You may want to have your friend or classmate prepare additional questions. Some boot exercises can be easily created from the Scenario and Solution list in Chapter 16. Other exercises on network services can be created based on what you've learned in Chapters 7 and 9–15. Exercises related to adding, removing, and resizing logical volumes can be developed from the information in Chapter 8.

In these exercises, you'll be working with an RHEL computer with some key files messed up. Ideally, you'll have a friend or classmate help you prepare your computer. Assume that you have a network server with the RHEL installation files. This should be on a system with some free unpartitioned space on the hard drive, and one filesystem, /tmp, on a logical volume.

You'll also need a computer on which you can boot directly from your CD drive, so you can use the first Red Hat installation CD. (If you can boot from the USB, you can substitute a specially prepared boot USB drive described in Chapter 2.) Then walk away, and have the colleague who is preparing the exam take the following steps:

  1. Copy and back up the /etc/inittab configuration file. One possible name is /etc/bak.inittab.

  2. Open /etc/inittab file in a text editor.

  3. Change the x in the id:x:initdefault line to 4.

  4. Comment out the l4:4:wait:/etc/rc.d/rc 4 line in /etc/inittab. Save your changes.

  5. Activate SELinux in enforcing mode.

  6. Change the kernel directive in the GRUB configuration file (/boot/grub/grub.conf), to point the root directive as shown:


  7. Open /etc/fstab, and comment out the directive associated with the /boot directory filesystem; the result should be similar to:

     LABEL=/boot /boot ext3 defaults 1 2 

  8. Make sure that the Apache, NFS, sendmail, and vsFTP services aren't set to start in runlevel 4, but are set to start in other standard runlevels (2, 3, and 5). To make this work, you can use commands such as:

     # chkconfig httpd on # chkconfig httpd --level 4 off 

  9. Disable SELinux protection for the Apache, NFS, and vsFTP server daemons. Use the SELinux Management Tool.

  10. Set up a regular standard firewall with the system-config-securitylevel command. Don't allow in any special traffic.

  11. Check your /etc/hosts.allow and /etc/hosts.deny files. If there are rules related to ftpd or ALL services in either file, comment them out.

  12. Open the Samba configuration file, and comment out the [homes] stanza. If required, in the SELinux Management tool, disable the Allow Samba To Share Users Home Directories option.

  13. Make sure you have a boot disc or USB key that can serve as a rescue disc. As the Red Hat Exam Prep guide requires the use of the first RHEL installation CD as a rescue disc, make sure your computer can boot from this CD.

  14. Use the poweroff command to stop Linux.

  15. Tell the RHCE candidate that he or she will face a challenge during the boot process, will need to make sure /boot is properly mounted, and will need to reduce the space available to the /tmp filesystem on a logical volume. Ask the candidate to make sure the NFS, sendmail, Apache, and vsFTP services are working and available to other systems. Suggest that if SELinux is deactivated, everything else has to be done perfectly.

RHCE Red Hat Certified Engineer Linux Study Guide (Exam RH302)
Linux Patch Management: Keeping Linux Systems Up To Date
ISBN: 0132366754
EAN: 2147483647
Year: 2004
Pages: 227
Authors: Michael Jang © 2008-2017.
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