Alright, something that’s not exactly fun but is definitely necessary: analyzing core dumps using the crash utility in Red Hat Enterprise Linux 7. This tutorial will be a bit more casual than your typical tech guide because we all know how boring it can get to read through endless lines of code and technical jargon. So, let’s make this as painless (and entertaining) as possible!

To start: what is a core dump? A core dump occurs when a program crashes unexpectedly or receives an error that causes the kernel to terminate it. The system then creates a file called “core” in the directory where the program was running, which contains the memory contents of the process at the time of its failure. This can be incredibly helpful for debugging and identifying issues with your code.

Now how to analyze these core dumps using Red Hat Enterprise Linux 7’s crash utility. Here are some simple steps:

1. Install the necessary packages: To install the crash analyzing tool, execute this command as root in a shell prompt: `yum install crash`

2. Also, make sure to install the kernel-debuginfo package that corresponds to your running kernel using this command: `debuginfo-install kernel`

3. Once you have installed these packages, navigate to the directory where the core dump file is located and run the following command at a shell prompt: `crash /usr/lib/debug/lib/modules//vmlinux \ /var/crash//vmcore`

Make sure you replace with your kernel version, which can be found using the uname -r command. And don’t forget to use the timestamp of when the core dump occurred in place of .

4. Once crash is running, type `log` at the interactive prompt to display the kernel message buffer. This will show you any error messages or other relevant information that may have led up to the program crashing.

5. To exit the utility and terminate crash, simply type `exit` or `q`.

Now some frequently asked questions:

– What considerations need to be made for using Kdump in a clustered environment?

If you are running Red Hat Enterprise Linux 6 or 7 High Availability Add-On, there are specific options available that can help with this. For more information on how to configure kdump for use with the HA Add-On, check out this article: https://access.redhat.com/documentation/en-us/red_hat_enterprise_linux/6/html/high_availability_add-on_administration/configuring_kdump

– How do I capture the boot log?

If there is a problem booting the second kernel, it’s necessary to review the early boot logs. To enable access to these messages, you can follow this tutorial: https://access.redhat.com/documentation/en-us/red_hat_enterprise_linux/7/html/system_administrators_guide/configuring_serial_console

– How do I increase the messaging from makedumpfile for debugging?

If you need to see more detailed information in your core dump, you can modify the makedumpfile script. For instructions on how to do this, check out this article: https://access.redhat.com/documentation/en-us/red_hat_enterprise_linux/7/html/system_administrators_guide/debugging_kernel_problems

Analyzing core dumps using the crash utility in Red Hat Enterprise Linux 7 is not as scary as it sounds. Just remember to follow these simple steps and refer back to this tutorial if needed.