Chapter 4. Creating a bootable installation medium for RHEL
Chapter 4. Creating a bootable installation medium for RHEL You can download the ISO file from the Customer Portal to prepare the bootable physical installation medium, such as a USB or DVD. Starting with RHEL 8, Red Hat no longer provides separate variants for Server and Workstation . Red Hat Enterprise Linux for x86_64 includes both Server and Workstation capabilities. The distinction between Server and Workstation is managed through the System Purpose Role during the installation or configuration process. After downloading an ISO file from the Customer Portal, create a bootable physical installation medium, such as a USB or DVD to continue the installation process. For secure environment cases where USB drives are prohibited, consider using the Image Builder to create and deploy reference images. This method ensures compliance with security policies while maintaining system integrity. For more details, refer to the Image builder documentation . 4.1. Installation boot media options There are several options available to boot the Red Hat Enterprise Linux installation program. Full installation DVD or USB flash drive Create a full installation DVD or USB flash drive using the DVD ISO image. The DVD or USB flash drive can be used as a boot device and as an installation source for installing software packages. Minimal installation DVD, CD, or USB flash drive Create a minimal installation CD, DVD, or USB flash drive using the Boot ISO image, which contains only the minimum files necessary to boot the system and start the installation program. If you are not using the Content Delivery Network (CDN) to download the required software packages, the Boot ISO image requires an installation source that contains the required software packages. 4.2. Creating a bootable DVD You can create a bootable installation DVD by using a burning software and a DVD burner. The exact steps to produce a DVD from an ISO image file vary greatly, depending on the operating system and disc burning software installed. Consult your system's burning software documentation for the exact steps to burn a DVD from an ISO image file. Warning You can create a bootable DVD using either the DVD ISO image (full install) or the Boot ISO image (minimal install). However, the DVD ISO image is larger than 4.7 GB, and as a result, it might not fit on a single or dual-layer DVD. Check the size of the DVD ISO image file before you proceed. Use a USB flash drive when using the DVD ISO image to create bootable installation media. For the environment cases where USB drives are prohibited, see Image builder documentation . 4.3. Creating a bootable USB device on Linux You can create a bootable USB device which you can then use to install Red Hat Enterprise Linux on other machines. This procedure overwrites the existing data on the USB drive without any warning. Back up any data or use an empty flash drive. A bootable USB drive cannot be used for storing data. Prerequisites You have downloaded the full installation DVD ISO or minimal installation Boot ISO image from the Product Downloads page. You have a USB flash drive with enough capacity for the ISO image. The required size varies, but the recommended USB size is 8 GB. Procedure Connect the USB flash drive to the system. Open a terminal window and display a log of recent events. Messages resulting from the attached USB flash drive are displayed at the bottom of the log. Record the name of the connected device. Log in as a root user: Enter your root password when prompted. Find the device node assigned to the drive. In this example, the drive name is sdd . If the inserted USB device mounts automatically, unmount it before continuing with the steps. For unmounting, use the umount command. For more information, see Unmounting a file system with umount . Write the ISO image directly to the USB device: Replace /image_directory/image.iso with the full path to the ISO image file that you downloaded, Replace device with the device name that you retrieved with the dmesg command. In this example, the full path to the ISO image is /home/testuser/Downloads/rhel-9-x86_64-boot.iso , and the device name is sdd : Partition names are usually device names with a numerical suffix. For example, sdd is a device name, and sdd1 is the name of a partition on the device sdd . Wait for the dd command to finish writing the image to the device. Run the sync command to synchronize cached writes to the device. The data transfer is complete when the # prompt appears. When you see the prompt, log out of the root account and unplug the USB drive. The USB drive is now ready to use as a boot device. 4.4. Creating a bootable USB device on Windows You can create a bootable USB device on a Windows system with various tools. You can use Fedora Media Writer, available for download at https://github.com/FedoraQt/MediaWriter/releases . Fedora Media Writer is a community product and is not supported by Red Hat. You can report any issues with the tool at https://github.com/FedoraQt/MediaWriter/issues . Creating a bootable drive overwrites existing data on the USB drive without any warning. Back up any data or use an empty flash drive. A bootable USB drive cannot be used for storing data. Prerequisites You have downloaded the full installation DVD ISO or minimal installation Boot ISO image from the Product Downloads page. You have a USB flash drive with enough capacity for the ISO image. The required size varies. Procedure Download and install Fedora Media Writer from https://github.com/FedoraQt/MediaWriter/releases . Connect the USB flash drive to the system. Open Fedora Media Writer. From the main window, click Custom Image and select the previously downloaded Red Hat Enterprise Linux ISO image. From the Write Custom Image window, select the drive that you want to use. Click Write to disk . The boot media creation process starts. Do not unplug the drive until the operation completes. The operation may take several minutes, depending on the size of the ISO image, and the write speed of the USB drive. When the operation completes, unmount the USB drive. The USB drive is now ready to be used as a boot device. 4.5. Creating a bootable USB device on macOS You can create a bootable USB device which you can then use to install Red Hat Enterprise Linux on other machines. Creating a bootable USB drive overwrites any data previously stored on the USB drive without any warning. Back up any data or use an empty flash drive. A bootable USB drive cannot be used for storing data. Prerequisites You have downloaded the full installation DVD ISO or minimal installation Boot ISO image from the Product Downloads page. You have a USB flash drive with enough capacity for the ISO image. The required size varies. Procedure Connect the USB flash drive to the system. Identify the device path with the diskutil list command. The device path has the format of /dev/disknumber , where number is the number of the disk. The disks are numbered starting at zero (0). Typically, disk0 is the OS X recovery disk, and disk1 is the main OS X installation. In the following example, the USB device is disk2 : Identify your USB flash drive by comparing the NAME, TYPE and SIZE columns to your flash drive. For example, the NAME should be the title of the flash drive icon in the Finder tool. You can also compare these values to those in the information panel of the flash drive. Unmount the flash drive's file system volumes: When the command completes, the icon for the flash drive disappears from your desktop. If the icon does not disappear, you may have selected the wrong disk. Attempting to unmount the system disk accidentally returns a failed to unmount error. Write the ISO image to the flash drive. macOS provides both a block ( /dev/disk* ) and character device ( /dev/rdisk* ) file for each storage device. Writing an image to the /dev/rdisknumber character device is faster than writing to the /dev/disknumber block device. For example, to write the /Users/user_name/Downloads/rhel-9-x86_64-boot.iso file to the /dev/rdisk2 device, enter the following command: if= - Path to the installation image. of= - The raw disk device (/dev/rdisknumber) representing the target disk. bs=512K - Sets the block size to 512 KB for faster data transfer. status=progress - Displays a progress indicator during the operation. Wait for the dd command to finish writing the image to the device. The data transfer is complete when the # prompt appears. When the prompt is displayed, log out of the root account and unplug the USB drive. The USB drive is now ready to be used as a boot device. Additional resources Configuring System Purpose ISO for RHEL 8/9 Server or Workstation (Red Hat Knowledgebase)
dmesg|tail su - dmesg|tail [288954.686557] usb 2-1.8: New USB device strings: Mfr=0, Product=1, SerialNumber=2 [288954.686559] usb 2-1.8: Product: USB Storage [288954.686562] usb 2-1.8: SerialNumber: 000000009225 [288954.712590] usb-storage 2-1.8:1.0: USB Mass Storage device detected [288954.712687] scsi host6: usb-storage 2-1.8:1.0 [288954.712809] usbcore: registered new interface driver usb-storage [288954.716682] usbcore: registered new interface driver uas [288955.717140] scsi 6:0:0:0: Direct-Access Generic STORAGE DEVICE 9228 PQ: 0 ANSI: 0 [288955.717745] sd 6:0:0:0: Attached scsi generic sg4 type 0 [288961.876382] sd 6:0:0:0: sdd Attached SCSI removable disk dd if=/image_directory/image.iso of=/dev/device dd if=/home/testuser/Downloads/rhel-9-x86_64-boot.iso of=/dev/sdd diskutil list /dev/disk0 #: TYPE NAME SIZE IDENTIFIER 0: GUID_partition_scheme *500.3 GB disk0 1: EFI EFI 209.7 MB disk0s1 2: Apple_CoreStorage 400.0 GB disk0s2 3: Apple_Boot Recovery HD 650.0 MB disk0s3 4: Apple_CoreStorage 98.8 GB disk0s4 5: Apple_Boot Recovery HD 650.0 MB disk0s5 /dev/disk1 #: TYPE NAME SIZE IDENTIFIER 0: Apple_HFS YosemiteHD *399.6 GB disk1 Logical Volume on disk0s1 8A142795-8036-48DF-9FC5-84506DFBB7B2 Unlocked Encrypted /dev/disk2 #: TYPE NAME SIZE IDENTIFIER 0: FDisk_partition_scheme *8.1 GB disk2 1: Windows_NTFS SanDisk USB 8.1 GB disk2s1 diskutil unmountDisk /dev/disknumber Unmount of all volumes on disknumber was successful sudo dd if= /Users/user_name/Downloads/rhel-9-x86_64-boot.iso of= /dev/rdisk2 bs= 512K status= progress