Chapter 7. Preparing a PXE installation source

1. Export the installation ISO image or the installation tree to an NFS, HTTPS, HTTP, or FTP server.
2. Configure the HTTP or TFTP server and DHCP server, and start the HTTP or TFTP service on the server.
3. Boot the client and start the installation.

Procedure

1. Install the DHCP server:

   # dnf install kea

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2. Set up a DHCPv4 server. Enter the following configuration in the /etc/kea/kea-dhcp4.conf file. Replace the addresses to match your network card.

   {
     "Dhcp4": {
       "interfaces-config": {
         "interfaces": [ "enp1s0" ]
       },
       "subnet4": [
         {
           "id": 1,
           "subnet": "192.168.124.0/24",
           "pools": [
             {
               "pool": "192.168.124.100 - 192.168.124.200"
             }
           ],
           "option-data": [
             {
               "space": "dhcp4",
               "name": "routers",
               "code": 3,
               "data": "192.168.124.10"
             },
             {
               "space": "dhcp4",
               "name": "domain-name-servers",
               "code": 6,
               "data": "192.168.124.10"
             }
           ]
         }
       ],
       "client-classes": [
         {
           "name": "uefi PXE Clients",
           "test": "substring(option[60].hex,0,9) == 'PXEClient' and option[93].hex == 0x0007",
           "next-server": "192.168.124.2",
           "boot-file-name": "/uefi/BOOT/BOOTX64.EFI"
         },
         {
           "name": "bios PXE Clients",
           "test": "substring(option[60].hex,0,9) == 'PXEClient' and option[93].hex == 0x0000",
           "next-server": "192.168.124.2",
           "boot-file-name": "syslinux/pxelinux.0"
         },
         {
           "name": "uefi HTTP Clients",
           "test": "substring(option[60].hex,0,10) == 'HTTPClient' and option[93].hex == 0x0007",
           "option-data": [
             {
               "space": "dhcp4",
               "name": "vendor-class-identifier",
               "code": 60,
               "data": "HTTPClient"
             }
           ],
           "next-server": "192.168.124.2",
           "boot-file-name": "http://192.168.124.2/uefi/BOOT/BOOTX64.EFI"
         }
       ]
     }
   }

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3. Start the DHCPv4 service:

   # systemctl enable --now kea-dhcp4

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Procedure

1. Install the DHCP server:

   # dnf install kea

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2. Set up a DHCPv6 server. Enter the following configuration in the /etc/kea/kea-dhcp6.conf file. Replace the addresses to match your network card.

   {
     "Dhcp6": {
       "interfaces-config": {
         "interfaces": [ "enp1s0" ]
       },
       "subnet6": [
         {
           "id": 1,
           "subnet": "fd33::/64",
           "interface": "enp1s0",
           "pools": [
             {
               "pool": "fd33::100-fd33::200"
             }
           ]
         }
       ],
       "client-classes": [
         {
           "name": "uefi PXE Clients",
           "test": "substring(option[16].hex,6,9) == 'PXEClient' and substring(option[16].hex,21,5) == '00007'",
           "option-data": [
             {
               "space": "dhcp6",
               "name": "bootfile-url",
               "code": 59,
               "data": "tftp://[fd33::2]/uefi/BOOT/BOOTX64.EFI"
             }
           ]
         },
         {
           "name": "bios PXE Clients",
           "test": "substring(option[16].hex,6,9) == 'PXEClient' and substring(option[16].hex,21,5) == '00000'",
           "option-data": [
             {
               "space": "dhcp6",
               "name": "bootfile-url",
               "code": 59,
               "data": "tftp://[fd33::2]/syslinux/pxelinux.0"
             }
           ]
         },
         {
           "name": "uefi HTTP Clients",
           "test": "substring(option[16].hex,6,10) == 'HTTPClient' and substring(option[16].hex,22,5) == '00007'",
           "option-data": [
             {
               "space": "dhcp6",
               "name": "bootfile-url",
               "code": 59,
               "data": "http://[fd33::2]/uefi/BOOT/BOOTX64.EFI"
             }
           ]
         }
       ]
     }
   }

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3. Start the DHCPv6 service:

   # systemctl enable --now kea-dhcp6

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4. If DHCPv6 packets are dropped by the RP filter in the firewall, check its log. If the log contains the rpfilter_DROP entry, disable the filter using the following configuration in the /etc/firewalld/firewalld.conf file:

   IPv6_rpfilter=no

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Procedure

1. As root, install the following package.

   # dnf install tftp-server

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2. Allow incoming connections to the tftp service in the firewall:

   # firewall-cmd --add-service=tftp

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   This command enables temporary access until the next server reboot.

3. Optional: To enable permanent access, repeat the previous command together with the --permanent option.

   Depending on the location of the installation ISO file, you might have to allow incoming connections for HTTP or other services.

4. Install syslinux-tftpboot package:

   # dnf -y install syslinux-tftpboot

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5. Create a pxelinux directory in the /var/lib/tftpboot directory and copy all the files provided by the syslinux-tftpboot package (located in /tftpboot directory) into the pxelinux directory:

   # mkdir /var/lib/tftpboot/pxelinux
   # cp /tftpboot/* /var/lib/tftpboot/pxelinux

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6. Create the directory pxelinux.cfg in the pxelinux directory:

   # mkdir /var/lib/tftpboot/pxelinux/pxelinux.cfg

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7. Create a configuration file named default and add it to the pxelinux.cfg directory as shown in the following example:

   DEFAULT menu.c32
   
   MENU TITLE Red Hat Enterprise Linux 10.0 Installation
   TIMEOUT 600
   
   LABEL default
   	MENU LABEL ^Install Red Hat Enterprise Linux 10.0
   	KERNEL /pxelinux/images/RHEL-10/vmlinuz
   	APPEND initrd=/pxelinux/images/RHEL-10/initrd.img inst.repo=http://192.168.124.2/redhat/iso quiet
   
   LABEL text
   	MENU LABEL Install Red Hat Enterprise Linux 10.0 in ^text mode
   	KERNEL /pxelinux/images/RHEL-10/vmlinuz
   	APPEND initrd=/pxelinux/images/RHEL-10/initrd.img inst.repo=http://192.168.124.2/redhat/iso inst.text quiet
   
   LABEL rescue
   	MENU LABEL ^Rescue a Red Hat Enterprise Linux system
   	KERNEL /pxelinux/images/RHEL-10/vmlinuz
   	APPEND initrd=/pxelinux/images/RHEL-10/initrd.img inst.stage2=http://192.168.124.2/redhat/iso inst.rescue quiet
   
   LABEL local
   	MENU LABEL Boot from ^local drive
   	LOCALBOOT 0xffff

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   • The installation program cannot boot without its runtime image. Use the inst.stage2 boot option to specify location of the image. Alternatively, you can use the inst.repo= option to specify the image as well as the installation source.
   • The installation source location used with inst.repo must contain a valid .treeinfo file.
   • When you select the content of RHEL10 installation DVD as the installation source, the .treeinfo file points to the BaseOS and the AppStream repositories. You can use a single inst.repo option to load both repositories.

8. Create a subdirectory to store the boot image files in the /var/lib/tftpboot directory, and copy the boot image files to the directory. In this example, the directory is /var/lib/tftpboot/pxelinux/images/RHEL-10:

   # mkdir -p /var/lib/tftpboot/pxelinux/images/RHEL-10
   # cp /path_to_x86_64_images/pxeboot/{vmlinuz,initrd.img} /var/lib/tftpboot/pxelinux/images/RHEL-10/

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9. Start and enable the tftp.socket service:

   # systemctl enable --now tftp.socket

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   The PXE boot server is now ready to serve PXE clients. You can start the client, which is the system to which you are installing Red Hat Enterprise Linux. Select PXE Boot or Network Boot when prompted to specify a boot source, and start the network installation.

Procedure

1. As root, install the following package.

   # dnf install tftp-server

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2. Allow incoming connections to the tftp service in the firewall:

   # firewall-cmd --add-service=tftp

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   This command enables temporary access until the next server reboot.

3. Optional: To enable permanent access, repeat the previous command together with the --permanent option.

   Depending on the location of the installation ISO file, you might have to allow incoming connections for HTTP or other services.

4. Access the EFI boot image files from the DVD ISO image:

   # mount -t iso9660 /path_to_image/name_of_image.iso /mount_point -o loop,ro

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5. Copy the EFI boot images from the DVD ISO image:

   # mkdir /var/lib/tftpboot/redhat
   # cp -r /mount_point/EFI /var/lib/tftpboot/redhat/

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6. Create a subdirectory to store the boot image files in the /var/lib/tftpboot/ directory, and copy the boot image files to the directory. In this example, the directory is /var/lib/tftpboot/images/RHEL-10/:

   # mkdir -p /var/lib/tftpboot/images/RHEL-10/
   # cp /mount_point/images/pxeboot/{vmlinuz,initrd.img} /var/lib/tftpboot/images/RHEL-10/
   # umount /mount_point

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7. Fix the permissions of the copied files:

   # chmod -R 755 /var/lib/tftpboot/redhat/

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8. Replace the content of /var/lib/tftpboot/redhat/EFI/BOOT/grub.cfg with the following example:

   set default="1"
   set timeout=60
   
   function load_video {
     insmod efi_gop
     insmod efi_uga
     insmod video_bochs
     insmod video_cirrus
     insmod all_video
   }
   
   load_video
   set gfxpayload=keep
   
   menuentry 'Install Red Hat Enterprise Linux 10.0' --class fedora --class gnu-linux --class gnu --class os {
       	linuxefi /images/RHEL-10/vmlinuz inst.repo=http://192.168.124.2/redhat/iso quiet
       	initrdefi /images/RHEL-10/initrd.img
   }
   submenu 'Troubleshooting -->' {
       	menuentry 'Install Red Hat Enterprise Linux 10.0 in text mode' --class fedora --class gnu-linux --class gnu --class os {
               	linuxefi /images/RHEL-10/vmlinuz inst.repo=http://192.168.124.2/redhat/iso inst.text quiet
               	initrdefi /images/RHEL-10/initrd.img
       	}
       	menuentry 'Rescue a Red Hat Enterprise Linux system' --class fedora --class gnu-linux --class gnu --class os {
               	linuxefi /images/RHEL-10/vmlinuz inst.stage2=http://192.168.124.2/redhat/iso inst.rescue quiet
               	initrdefi /images/RHEL-10/initrd.img
       	}
   }

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   • The installation program cannot boot without its runtime image. Use the inst.stage2 boot option to specify location of the image. Alternatively, you can use the inst.repo= option to specify the image as well as the installation source.
   • The installation source location used with inst.repo must contain a valid .treeinfo file.
   • When you select the RHEL10 installation DVD as the installation source, the .treeinfo file points to the BaseOS and the AppStream repositories. You can use a single inst.repo option to load both repositories.

9. Start and enable the tftp.socket service:

   # systemctl enable --now tftp.socket

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   The PXE boot server is now ready to serve PXE clients. You can start the client, which is the system to which you are installing Red Hat Enterprise Linux. Select PXE Boot or Network Boot when prompted to specify a boot source, and start the network installation.