Hardware Troubleshooting Labs

You may run this lab on either VM.

1. Identifying Hardware

Goal

  • Catalog your system hardware

    1. Find all Ethernet controllers.

      # lspci |grep Ethernet

    2. List all USB devices.

      # lsusb

    3. Find the vendor, version, and release date of the system BIOS.

      # dmidecode --type bios | grep -E "Vendor|Version|Release Date"

    4. Get information on the location and size of the physical memory modules.

      # dmidecode --type memory |grep -E "Locator|Size"

    5. Get detailed information on the x86 CPU.

      # yum -y install x86info
# x86info -c

2. Diagnosing Memory Failures

Goals

  • Test your server’s memory

  • Configure the system to be able to boot in to the memory test program

  • Evaluate the memory on the system for errors

You have a server that is logging strange errors. Another system administrator suspects some of its memory may be failing.

Install the memory test program provided with Red Hat Enterprise Linux on server1 and make it an option in the GRUB menu. Once this is deployed, reboot your server and run the memory checker.

  1. Use the following yum command to determine the package name.

    The memtest86+ package provides the memory test program.

    [root@server1 ~]# yum list available | grep memtest
memtest86+.x86_64                      4.20-12.el7                         rhel7

  2. Once you know the package name, use yum to install it.

    [root@server1 ~]# yum install -y memtest86+

  3. Use rpm to list the package contents once it is installed.

    This will help you determine the name of the utility used to modify the GRUB menu.

    [root@server1 ~]# rpm -ql memtest86+
/boot/elf-memtest86+-4.20
/boot/memtest86+-4.20
/etc/grub.d/20_memtest86+
/usr/sbin/memtest-setup
/usr/sbin/new-memtest-pkg
/usr/share/doc/memtest86+-4.20
/usr/share/doc/memtest86+-4.20/README
/usr/share/memtest86+
/usr/share/memtest86+/20_memtest86+
[root@server1 ~]# memtest-setup
grub2 detected, installing template...
grub 2 template installed.
Do not forget to regenerate your grub.cfg by:
  # grub2-mkconfig -o /boot/grub2/grub.cfg
Setup complete.
[root@server1 ~]# grub2-mkconfig -o /boot/grub2/grub.cfg
Generating grub configuration file ...
Found linux image: /boot/vmlinuz-3.10.0-123.el7.x86_64
Found initrd image: /boot/initramfs-3.10.0-123.el7.x86_64.img
Found linux image: /boot/vmlinuz-0-rescue-2f7e407938c64980b13961ca0708f2d6
Found initrd image: /boot/initramfs-0-rescue-2f7e407938c64980b13961ca0708f2d6.img
Found memtest image: /boot/elf-memtest86+-4.20
done

  4. Reboot server1 and select the memory test program from the GRUB menu.

    Let the program run for a couple minutes.

    [root@server1 ~]# reboot