Chapter 2. Preparing for your installation

Procedure

1. Open the browser and access https://access.redhat.com/downloads/content/rhel.

   This page lists popular downloads for Red Hat Enterprise Linux.

2. Click Download Now beside the ISO image that you require.

3. If the desired version of RHEL is not listed, click All Red Hat Enterprise Linux Downloads.

   1. From the Product Variant drop-down menu, select the variant and architecture that you require.

      • Optional: Select the Packages tab to view the packages contained in the selected variant. For information about the packages available in Red Hat Enterprise Linux 8, see the Package Manifest document.

   2. From the Version drop-down menu, select the RHEL version you want to download. By default, the latest version for the selected variant and architecture is selected.

      The Product Software tab displays the image files, which include:

      • Red Hat Enterprise Linux Binary DVD image.
      • Red Hat Enterprise Linux Boot ISO image.

      Additional images may be available, for example, preconfigured virtual machine images.

   3. Click Download Now beside the ISO image that you require.

Procedure

1. Create a bash file with the following content:

   #!/bin/bash
   # set the offline token and checksum parameters
   offline_token="<offline_token>"
   checksum=<checksum>
   
   # get an access token
   access_token=$(curl https://sso.redhat.com/auth/realms/redhat-external/protocol/openid-connect/token -d grant_type=refresh_token -d client_id=rhsm-api -d refresh_token=$offline_token | jq -r '.access_token')
   
   # get the filename and download url
   image=$(curl -H "Authorization: Bearer $access_token" "https://api.access.redhat.com/management/v1/images/$checksum/download")
   filename=$(echo $image | jq -r .body.filename)
   url=$(echo $image | jq -r .body.href)
   
   # download the file
   curl $url -o $filename

   In the text above, replace <offline_token> with the token collected from the Red Hat API portal and <checksum> with the checksum value taken from the Product Downloads page.

2. Make this file executable.

   $ chmod u+x FILEPATH/FILENAME.sh

3. Open a terminal window and execute the bash file.

   $ ./FILEPATH/FILENAME.sh

Procedure

1. Connect the USB flash drive to the system.

2. Open a terminal window and display a log of recent events.

   $ dmesg|tail

   Messages resulting from the attached USB flash drive are displayed at the bottom of the log. Record the name of the connected device.

3. Log in as a root user:

   $ su -

   Enter your root password when prompted.

4. Find the device node assigned to the drive. In this example, the drive name is sdd.

   # 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

5. Write the ISO image directly to the USB device:

   # dd if=/image_directory/image.iso of=/dev/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-8-x86_64-boot.iso, and the device name is sdd:

     # dd if=/home/testuser/Downloads/rhel-8-x86_64-boot.iso of=/dev/sdd

     Note

     Ensure that you use the correct device name, and not the name of a partition on the device. 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.

6. 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.

Procedure

1. Download and install Fedora Media Writer from https://github.com/FedoraQt/MediaWriter/releases.
2. Connect the USB flash drive to the system.
3. Open Fedora Media Writer.
4. From the main window, click Custom Image and select the previously downloaded Red Hat Enterprise Linux ISO image.
5. From the Write Custom Image window, select the drive that you want to use.
6. 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.
7. When the operation completes, unmount the USB drive. The USB drive is now ready to be used as a boot device.

Procedure

1. Connect the USB flash drive to the system.

2. 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:

   $ 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

3. 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.

4. Unmount the flash drive’s filesystem volumes:

   $ diskutil unmountDisk /dev/disknumber
   					Unmount of all volumes on disknumber was successful

   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.

5. Write the ISO image to the flash drive:

   # sudo dd if=/path/to/image.iso of=/dev/rdisknumber

   Note

   Mac OS X 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-8-x86_64-boot.iso file to the /dev/rdisk2 device, enter the following command:

   # sudo dd if=/Users/user_name/Downloads/rhel-8-x86_64-boot.iso of=/dev/rdisk2

6. 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.

Procedure

1. Install the nfs-utils package:

   # yum install nfs-utils

2. Copy the DVD ISO image to a directory on the NFS server.

3. Open the /etc/exports file using a text editor and add a line with the following syntax:

   /exported_directory/ clients

   • Replace /exported_directory/ with the full path to the directory with the ISO image.

   • Replace clients with one of the following:

     • The host name or IP address of the target system
     • The subnetwork that all target systems can use to access the ISO image
     • To allow any system with network access to the NFS server to use the ISO image, the asterisk sign (*)

     See the exports(5) man page for detailed information about the format of this field.

     For example, a basic configuration that makes the /rhel8-install/ directory available as read-only to all clients is:

     /rhel8-install *

4. Save the /etc/exports file and exit the text editor.

5. Start the nfs service:

   # systemctl start nfs-server.service

   If the service was running before you changed the /etc/exports file, reload the NFS server configuration:

   # systemctl reload nfs-server.service

   The ISO image is now accessible over NFS and ready to be used as an installation source.

Procedure

1. Copy the DVD ISO image to the HTTP(S) server.

2. Create a suitable directory for mounting the DVD ISO image, for example:

   # mkdir /mnt/rhel8-install/

3. Mount the DVD ISO image to the directory:

   # mount -o loop,ro -t iso9660 /image_directory/image.iso /mnt/rhel8-install/

   Replace /image_directory/image.iso with the path to the DVD ISO image.

4. Copy the files from the mounted image to the HTTP(S) server root.

   # cp -r /mnt/rhel8-install/ /var/www/html/

   This command creates the /var/www/html/rhel8-install/ directory with the content of the image. Note that some other copying methods might skip the .treeinfo file which is required for a valid installation source. Entering the cp command for entire directories as shown in this procedure copies .treeinfo correctly.

5. Start the httpd service:

   # systemctl start httpd.service

   The installation tree is now accessible and ready to be used as the installation source.

   Note

   When configuring the installation source, use http:// or https:// as the protocol, the server host name or IP address, and the directory that contains the files from the ISO image, relative to the HTTP server root. For example, if you use HTTP, the server host name is myserver.example.com, and you have copied the files from the image to /var/www/html/rhel8-install/, specify http://myserver.example.com/rhel8-install/ as the installation source.

Procedure

1. Open and edit the /etc/vsftpd/vsftpd.conf configuration file in a text editor.

   1. Change the line anonymous_enable=NO to anonymous_enable=YES
   2. Change the line write_enable=YES to write_enable=NO.

   3. Add lines pasv_min_port=<min_port> and pasv_max_port=<max_port>. Replace <min_port> and <max_port> with the port number range used by FTP server in passive mode, for example, 10021 and 10031.

      This step might be necessary in network environments featuring various firewall/NAT setups.

   4. Optional: Add custom changes to your configuration. For available options, see the vsftpd.conf(5) man page. This procedure assumes that default options are used.

      Warning

      If you configured SSL/TLS security in your vsftpd.conf file, ensure that you enable only the TLSv1 protocol, and disable SSLv2 and SSLv3. This is due to the POODLE SSL vulnerability (CVE-2014-3566). See https://access.redhat.com/solutions/1234773 for details.

2. Configure the server firewall.

   1. Enable the firewall:

      # systemctl enable firewalld

   2. Start the firewall:

      # systemctl start firewalld

   3. Configure the firewall to allow the FTP port and port range from the previous step:

      # firewall-cmd --add-port min_port-max_port/tcp --permanent
      # firewall-cmd --add-service ftp --permanent

      Replace <min_port> and <max_port> with the port numbers you entered into the /etc/vsftpd/vsftpd.conf configuration file.

   4. Reload the firewall to apply the new rules:

      # firewall-cmd --reload

3. Copy the DVD ISO image to the FTP server.

4. Create a suitable directory for mounting the DVD ISO image, for example:

   # mkdir /mnt/rhel8-install

5. Mount the DVD ISO image to the directory:

   # mount -o loop,ro -t iso9660 /image-directory/image.iso /mnt/rhel8-install

   Replace /image-directory/image.iso with the path to the DVD ISO image.

6. Copy the files from the mounted image to the FTP server root:

   # mkdir /var/ftp/rhel8-install
   # cp -r /mnt/rhel8-install/ /var/ftp/

   This command creates the /var/ftp/rhel8-install/ directory with the content of the image. Note that some copying methods can skip the .treeinfo file which is required for a valid installation source. Entering the cp command for whole directories as shown in this procedure will copy .treeinfo correctly.

7. Make sure that the correct SELinux context and access mode is set on the copied content:

   # restorecon -r /var/ftp/rhel8-install
   # find /var/ftp/rhel8-install -type f -exec chmod 444 {} \;
   # find /var/ftp/rhel8-install -type d -exec chmod 755 {} \;

8. Start the vsftpd service:

   # systemctl start vsftpd.service

   If the service was running before you changed the /etc/vsftpd/vsftpd.conf file, restart the service to load the edited file:

   # systemctl restart vsftpd.service

   Enable the vsftpd service to start during the boot process:

   # systemctl enable vsftpd

   The installation tree is now accessible and ready to be used as the installation source.

   Note

   When configuring the installation source, use ftp:// as the protocol, the server host name or IP address, and the directory in which you have stored the files from the ISO image, relative to the FTP server root. For example, if the server host name is myserver.example.com and you have copied the files from the image to /var/ftp/rhel8-install/, specify ftp://myserver.example.com/rhel8-install/ as the installation source.

Procedure

1. Download an ISO image of the Red Hat Enterprise Linux installation DVD. Alternatively, if you have the DVD on physical media, you can create an image of an ISO with the following command on a Linux system:

   dd if=/dev/dvd of=/path_to_image/name_of_image.iso

   where dvd is your DVD drive device name, name_of_image is the name you give to the resulting ISO image file, and path_to_image is the path to the location on your system where you want to store the image.

2. Copy and paste the ISO image onto the system hard drive or a USB drive.

3. Use a SHA256 checksum program to verify that the ISO image that you copied is intact. Many SHA256 checksum programs are available for various operating systems. On a Linux system, run:

   $ sha256sum /path_to_image/name_of_image.iso

   where name_of_image is the name of the ISO image file. The SHA256 checksum program displays a string of 64 characters called a hash. Compare this hash to the hash displayed for this particular image on the Downloads page in the Red Hat Customer Portal. The two hashes should be identical.

4. Specify the HDD installation source on the kernel command line before starting the installation:

   inst.repo=hd:<device>:/path_to_image/name_of_image.iso