Installing CentOS on IBM Power System accelerated servers

This guide helps you install CentOS 8 on an IBM Power Systems accelerated server (AC). Use these instructions for the following IBM Power System servers:

  • 8335-GTG (IBM Power System AC922)

  • 8335-GTH (IBM Power System AC922)

  • 8335-GTX (IBM Power System AC922)


Use this information to install CentOS 8 on a non-virtualized, or bare metal IBM Power System accelerated server. This procedure follows these general steps:

  • Connect to the BMC firmware to set up network connection

  • Choose your installation method:

    • Install CentOS 8 from USB device

    • Install CentOS 8 from network

  • Install CentOS 8

Additional resources

Completing the prerequisites and booting your firmware

Before you power on the system, ensure that you have the following items:

  • Ethernet cable

  • VGA monitor. The VGA resolution must be set to 1024x768-60Hz.

  • USB Keyboard

  • Power cords and outlet for your system

These instructions require that you have a network server set up with CentOS 7.x. Download CentOS 7.x LE ALT at

  1. Follow the link above to the CentOS Download page.

  2. Under the AltArch Releases heading, look for the ISO file for version 7, architecture "power9", and download it.

Complete these steps:

  • If your system belongs in a rack, install your system into that rack. For instructions, see IBM Power Systems information at

  • Connect an Ethernet cable to the embedded Ethernet port next to the serial port on the back of your system. Connect the other end to your network.

  • Connect your VGA monitor to the VGA port on back of system.

  • Connect your USB keyboard to an available USB port.

  • Connect the power cords to the system and plug them into the outlets.

At this point, your firmware is booting. Wait for the green LED on the power button to start flashing, indicating that it is ready to use. If your system does not have a green LED indicator light, then wait 1 to 2 minutes.

Configuring the firmware IP address

To set up or enable your network connection to the BMC firmware, use the Petitboot bootloader interface. Follow these steps:

  1. Power on your server using the power button on the front of your system. Your system will power on to the Petitboot bootloader menu. This process usually takes about 1 - 2 minutes to complete, but may take 5 - 10 minutes on the first boot or after a firmware update. Do not walk away from your system! When Petitboot loads, your monitor will become active and you will need to push any key in order to interrupt the boot process.

  2. At the Petitboot bootloader main menu, select Exit to Shell.

  3. Run ipmitool lan print 1. If this command returns an IP address, verify that is correct and continue to step 4. If no IP addresses are returned, follow these steps:

    1. Set the mode to static by running this command:

      ipmitool lan set 1 ipsrc static
    2. Set your IP address by running this command:

      ipmitool lan set 1 ipaddr _ip_address_

      Where ip_address is the static IP address that you are assigning to this system.

    3. Set your netmask by running this command:

      ipmitool lan set 1 netmask _netmask_address_

      Where netmask_address is the netmask for the system.

    4. Set your gateway server by running this command:

      ipmitool lan set 1 defgw ipaddr _gateway_server_
      Where gateway_server is the gateway for this system.
    5. Confirm the IP address by running the command ipmitool lan print 1 again.

      This interface is not active until after you perform the following steps.

    6. To reset your firmware, run the following command:

      ipmitool raw 0x06 0x40.

      This command must complete before continuing the process; however, it does not return any information. To verify that this command has completed, ping your system BMC address (the same IP address used in your IPMItool command). When the ping returns successfully, continue to the next step.

      Note: If your ping does not return successfully within a reasonable amount of time (2 - 3 minutes), try these additional steps

    7. Power your system off with this command: poweroff.h.

    8. Unplug the power cords from the back of the system. Wait 30 seconds and then apply power to boot BMC.

Powering on your server with OpenBMC commands

After your system powers on, the Petitboot interface loads. If you do not interrupt the boot process by pressing any key within 10 seconds, Petitboot automatically boots the first option.

To power on your server from a PC or notebook that is running Linux, follow these steps:

  • Default user name: root

  • Default password: 0penBmc (where, 0penBMC is using a zero and not a capital O)

    1. Open a terminal program on your PC or notebook.

    2. Log in to the BMC by running the following commands.

      ssh root@<BMC server_ip_address>
      root@<BMC server password>

      Where BMC server_ip_address is the IP address of the BMC and BMC server password is the password to authenticate.

    3. To power on your server, run the following command:

      $ root@witherspoon:~# obmcutil poweron
    4. Connect to OS console and use the default password 0penBmc.

      ssh -p 2200 root@<BMC server_ip_address> root@

Where BMC server_ip_address is the IP address of the BMC and BMC server password is the password to authenticate.

Choose your installation method on IBM accelerated servers

You can either install CentOS 8 from a USB device or through the network.

Configuring Petitboot for network installation

After the system powers on, the Petitboot bootloader scans local boot devices and network interfaces to find boot options that are available to the system. To install CentOS 8 from a network server, you need to set up a network interface (that is not the BMC network interface).

Set up a network connection and provide the network boot detail to Petitboot by following these steps:

  1. Connect an Ethernet cable to the second Ethernet port on the back of your system. Connect the other end to your network.

  2. On the Petitboot main screen, select c to configure your system options.

  3. In the Network field of the configuration screen, enter your network information:

    1. Select your network type

    2. Select your network device (remember the interface name and mac address)

    3. Specify your IP/mask, Gateway, and DNS server (remember these setting as you will need them in the next step)

    4. Select OK to return to the main menu.

  4. Back on the Petitboot main screen, select n to create new options.

  5. Choose your boot device or select to Specify paths/URLs manually and then enter your boot options:

    1. In the Kernel field, enter the path to the kernel. This field is mandatory. Enter a URL similar to this one for a network:

    2. In the Initrd field, enter the path to the init ramdisk. Enter a URL similar to this one for a network:

    3. In the Boot parameter field, set up the set up the repository path and the IP address of the server where the operating system is installed. For example:

      append repo=http://<http_server_ip>/ root=live:http://<http_server_ip>/os/LiveOS/squashfs.img ipv6.disable=1 ifname=<ethernet_interface_name>:<mac_addr> ip=<os ip>::<gateway>:<2 digit mask>:<hostname>:<ethernet_interface_name>:none nameserver=<anem_server> inst.text

      You can accept the defaults for the rest of the fields.

  6. After you set your netboot options, select OK and press Enter.

  7. On the Petitboot main window, select User Item 1 as your boot option and press Enter.

Configuring Petitboot for installation with USB device on accelerated servers

After the system powers on, the Petitboot bootloader scans local boot devices and network interfaces to find boot options that are available to the system. For information about creating a bootable USB device, see Creating a bootable USB device on Linux.

Use one of the following USB devices:

  • USB attached DVD player with a single USB cable to stay under 1.0 Amps

  • 8 GB 2.0 USB flash drive

Follow these steps to configure Petitboot:

  1. Insert your bootable USB device into the front USB port. Petitboot displays the following:

    [USB: sdb1 / 2015-10-30-11-05-03-00]
        Rescue a CentOS system (64-bit kernel)
        Test this media & install CentOS 8.x  (64-bit kernel)
      *  Install CentOS 8.x (64-bit kernel)

    Select Rescan devices if the USB device does not appear. If your device is not detected, you may have to try a different type.

  2. Record the UUID of the USB device. For example, the UUID of the USB device in the above example is 2015-10-30-11-05-03-00.

  3. Select CentOS 8.x (64-bit kernel) and press e (Edit) to open the Petitboot Option Editor window.

  4. Move the cursor to the Boot arguments section and add the following information:

           inst.text inst.stage2=hd:UUID=your_UUID
           where your_UUID is the UUID that you recorded.
           Petitboot Option Editor
                         Device:    ( ) sda2 [f8437496-78b8-4b11-9847-bb2d8b9f7cbd]
                                         (*) sdb1 [2015-10-30-11-05-03-00]
                                         ( ) Specify paths/URLs manually
                         Kernel:         /ppc/ppc64/vmlinuz
                         Initrd:         /ppc/ppc64/initrd.img
                         Device tree:
                         Boot arguments: ro inst.text inst.stage2=hd:UUID=2015-10-30-11-05-03-00
                            [    OK    ]  [   Help   ]  [  Cancel  ]
  5. Select OK to save your options and return to the Main menu.

  6. Verify that Install CentOS 8.x (64-bit kernel) is selected and then press Enter to begin your installation.

Completing your accelerated server installation

After you select to boot the CentOS 8 installer, the installer wizard walks you through the steps.

  1. Follow the installation wizard for CentOS to set up disk options, your user name and password, time zones, and so on. The last step is to restart your system.

    While your system is restarting, remove the USB device.

  2. After the system restarts, Petitboot displays the option to boot CentOS 8. Select this option and press Enter.