If you need to troubleshoot or repair your Red Hat Enterprise Linux system, you can use a rescue CD ISO image to boot into a minimal environment and access your files. In this article, we will show you how to download the rescue CD ISO image and use it to boot your system.
Downloading the rescue CD ISO image
To download the rescue CD ISO image, you need to have an active subscription to Red Hat Customer Portal. Follow these steps:
Visit https://access.redhat.com/downloads/ and log in with your credentials.
Select the product and version that matches your system. For example, Red Hat Enterprise Linux 8.
Click on the Binary DVD link under the Downloads section. This will download the full installation DVD image, which includes the rescue mode.
After the download is complete, verify the checksum of the ISO image using the md5sum command. For example:
The output should match the checksum provided on the download page.
Using the rescue CD ISO image
To use the rescue CD ISO image, you need to burn it to a CD or DVD, or write it to a USB stick. You can use any burning software or command-line tools to do this. For example, on Linux you can use the dd command:
This will write the ISO image to the USB device /dev/sdb. Make sure you replace /dev/sdb with the correct device name for your USB stick.
Once you have the rescue CD ready, you can boot your system from it. Follow these steps:
Insert the rescue CD into your system and restart it.
Press any key to enter the boot menu and select Troubleshooting > Rescue a Red Hat Enterprise Linux system.
The rescue mode will start and ask you if you want to mount your existing file systems. Choose Continue to mount them under /mnt/sysimage.
You will be dropped into a shell prompt where you can access your files and run commands. For example, you can use chroot to change the root directory to /mnt/sysimage and run commands as if you were in your normal system.
When you are done, type exit twice to exit the chroot and the shell. Then choose Reboot to restart your system normally.
We hope this article helped you learn how to download and use Redhat Rescue CD ISO image. For more information, please refer to the official documentation at https://access.redhat.com/documentation/en-us/red_hat_enterprise_linux/8/html/performing_an_advanced_rhel_installation/rescue-mode_installing-rhel-as-an-experienced-user.
Alternative ways to boot into rescue mode
If you don't have access to the rescue CD ISO image, or if you don't want to use it, you can also boot into rescue mode using other methods. Here are some alternatives:
If you have installed Red Hat Enterprise Linux using the Anaconda installer, you can use the installation media (CD, DVD, or USB) to boot into rescue mode. Just follow the same steps as above, but select the installation media instead of the rescue CD.
If you have a network connection and a PXE server, you can boot into rescue mode over the network. You need to configure your PXE server to provide the rescue image and the appropriate boot options. For more information, please refer to https://access.redhat.com/documentation/en-us/red_hat_enterprise_linux/8/html/performing_an_advanced_rhel_installation/booting-the-installation-remotely_installing-rhel-as-an-experienced-user.
If you have access to another Red Hat Enterprise Linux system, you can use it to boot your system into rescue mode using a tool called kexec. Kexec allows you to load a new kernel and initramfs without rebooting. You need to install the kexec-tools package and run the following commands:
This will load the rescue kernel and initramfs from your system and boot into it. Make sure you replace with the correct version of your kernel and with the correct device name for your root partition. For more information, please refer to https://access.redhat.com/documentation/en-us/red_hat_enterprise_linux/8/html/managing_systems_using_the_rhel_8_web_console/rebooting-systems-with-kexec_system-management-using-the-rhel-8-web-console.
We hope this article helped you learn how to download and use Redhat Rescue CD ISO image and some alternative ways to boot into rescue mode. For more information, please refer to the official documentation at https://access.redhat.com/documentation/en-us/red_hat_enterprise_linux/8/html/performing_an_advanced_rhel_installation/rescue-mode_installing-rhel-as-an-experienced-user. aa16f39245