Setup the drivers for the Bare Metal service

Setup the drivers for the Bare Metal service

PXE setup

If you will be using PXE, it needs to be set up on the Bare Metal service node(s) where ironic-conductor is running.

  1. Make sure the tftp root directory exist and can be written to by the user the ironic-conductor is running as. For example:

    sudo mkdir -p /tftpboot
    sudo chown -R ironic /tftpboot
  2. Install tftp server and the syslinux package with the PXE boot images:

    Ubuntu: (Up to and including 14.04)
        sudo apt-get install xinetd tftpd-hpa syslinux-common syslinux
    Ubuntu: (14.10 and after)
        sudo apt-get install xinetd tftpd-hpa syslinux-common pxelinux
    Fedora 21/RHEL7/CentOS7:
        sudo yum install tftp-server syslinux-tftpboot xinetd
    Fedora 22 or higher:
         sudo dnf install tftp-server syslinux-tftpboot xinetd
  3. Using xinetd to provide a tftp server setup to serve /tftpboot. Create or edit /etc/xinetd.d/tftp as below:

    service tftp
      protocol        = udp
      port            = 69
      socket_type     = dgram
      wait            = yes
      user            = root
      server          = /usr/sbin/in.tftpd
      server_args     = -v -v -v -v -v --map-file /tftpboot/map-file /tftpboot
      disable         = no
      # This is a workaround for Fedora, where TFTP will listen only on
      # IPv6 endpoint, if IPv4 flag is not used.
      flags           = IPv4

    and restart xinetd service:

        sudo service xinetd restart
        sudo systemctl restart xinetd
  4. Copy the PXE image to /tftpboot. The PXE image might be found at [1]:

    Ubuntu (Up to and including 14.04):
        sudo cp /usr/lib/syslinux/pxelinux.0 /tftpboot
    Ubuntu (14.10 and after):
        sudo cp /usr/lib/PXELINUX/pxelinux.0 /tftpboot
  5. If whole disk images need to be deployed via PXE-netboot, copy the chain.c32 image to /tftpboot to support it. The chain.c32 image might be found at:

    Ubuntu (Up to and including 14.04):
        sudo cp /usr/lib/syslinux/chain.c32 /tftpboot
    Ubuntu (14.10 and after):
        sudo cp /usr/lib/syslinux/modules/bios/chain.c32 /tftpboot
        sudo cp /boot/extlinux/chain.c32 /tftpboot
  6. If the version of syslinux is greater than 4 we also need to make sure that we copy the library modules into the /tftpboot directory [2] [1]:

        sudo cp /usr/lib/syslinux/modules/*/ldlinux.* /tftpboot
  7. Create a map file in the tftp boot directory (/tftpboot):

    echo 're ^(/tftpboot/) /tftpboot/\2' > /tftpboot/map-file
    echo 're ^/tftpboot/ /tftpboot/' >> /tftpboot/map-file
    echo 're ^(^/) /tftpboot/\1' >> /tftpboot/map-file
    echo 're ^([^/]) /tftpboot/\1' >> /tftpboot/map-file
[1](1, 2) On Fedora/RHEL the syslinux-tftpboot package already install the library modules and PXE image at /tftpboot. If the TFTP server is configured to listen to a different directory you should copy the contents of /tftpboot to the configured directory

PXE UEFI setup

If you want to deploy on a UEFI supported bare metal, perform these additional steps on the ironic conductor node to configure the PXE UEFI environment.

  1. Install Grub2 and shim packages:

    Ubuntu: (14.04LTS and later)
        sudo apt-get install grub-efi-amd64-signed shim-signed
    Fedora 21/RHEL7/CentOS7:
        sudo yum install grub2-efi shim
    Fedora 22 or higher:
        sudo dnf install grub2-efi shim
  2. Copy grub and shim boot loader images to /tftpboot directory:

    Ubuntu: (14.04LTS and later)
        sudo cp /usr/lib/shim/shim.efi.signed /tftpboot/bootx64.efi
        sudo cp /usr/lib/grub/x86_64-efi-signed/grubnetx64.efi.signed  \
    Fedora: (21 and later)
        sudo cp /boot/efi/EFI/fedora/shim.efi /tftpboot/bootx64.efi
        sudo cp /boot/efi/EFI/fedora/grubx64.efi /tftpboot/grubx64.efi
    CentOS: (7 and later)
        sudo cp /boot/efi/EFI/centos/shim.efi /tftpboot/bootx64.efi
        sudo cp /boot/efi/EFI/centos/grubx64.efi /tftpboot/grubx64.efi
  3. Create master grub.cfg:

    Ubuntu: Create grub.cfg under ``/tftpboot/grub`` directory.
    Fedora: Create grub.cfg under ``/tftpboot/EFI/fedora`` directory.
    CentOS: Create grub.cfg under ``/tftpboot/EFI/centos`` directory.
    Create directory GRUB_DIR
      sudo mkdir -p $GRUB_DIR

    This file is used to redirect grub to baremetal node specific config file. It redirects it to specific grub config file based on DHCP IP assigned to baremetal node.

    set default=master
    set timeout=5
    set hidden_timeout_quiet=false
    menuentry "master"  {
    configfile /tftpboot/$net_default_ip.conf

    Change the permission of grub.cfg:

    sudo chmod 644 $GRUB_DIR/grub.cfg
  4. Update the bare metal node with boot_mode capability in node’s properties field:

    ironic node-update <node-uuid> add properties/capabilities='boot_mode:uefi'
  5. Make sure that bare metal node is configured to boot in UEFI boot mode and boot device is set to network/pxe.

    NOTE: pxe_ilo driver supports automatic setting of UEFI boot mode and boot device on the bare metal node. So this step is not required for pxe_ilo driver.


For more information on configuring boot modes, see boot_mode_support.

Elilo: an alternative to Grub2

Elilo is a UEFI bootloader. It is an alternative to Grub2, although it isn’t recommended since it is not being supported.

  1. Download and untar the elilo bootloader version >= 3.16 from

    sudo tar zxvf elilo-3.16-all.tar.gz
  2. Copy the elilo boot loader image to /tftpboot directory:

    sudo cp ./elilo-3.16-x86_64.efi /tftpboot/elilo.efi
  3. Update bootfile and template file configuration parameters for UEFI PXE boot in the Bare Metal Service’s configuration file (/etc/ironic/ironic.conf):

    # Bootfile DHCP parameter for UEFI boot mode. (string value)
    # Template file for PXE configuration for UEFI boot loader.
    # (string value)

iPXE setup

An alternative to PXE boot, iPXE was introduced in the Juno release (2014.2.0) of Bare Metal service.

If you will be using iPXE to boot instead of PXE, iPXE needs to be set up on the Bare Metal service node(s) where ironic-conductor is running.

  1. Make sure these directories exist and can be written to by the user the ironic-conductor is running as. For example:

    sudo mkdir -p /tftpboot
    sudo mkdir -p /httpboot
    sudo chown -R ironic /tftpboot
    sudo chown -R ironic /httpboot
  2. Create a map file in the tftp boot directory (/tftpboot):

    echo 'r ^([^/]) /tftpboot/\1' > /tftpboot/map-file
    echo 'r ^(/tftpboot/) /tftpboot/\2' >> /tftpboot/map-file
  3. Set up TFTP and HTTP servers.

    These servers should be running and configured to use the local /tftpboot and /httpboot directories respectively, as their root directories. (Setting up these servers is outside the scope of this install guide.)

    These root directories need to be mounted locally to the ironic-conductor services, so that the services can access them.

    The Bare Metal service’s configuration file (/etc/ironic/ironic.conf) should be edited accordingly to specify the TFTP and HTTP root directories and server addresses. For example:

    # Ironic compute node's tftp root path. (string value)
    # IP address of Ironic compute node's tftp server. (string
    # value)
    # Ironic compute node's http root path. (string value)
    # Ironic compute node's HTTP server URL. Example:
    # (string value)
  4. Install the iPXE package with the boot images:

        apt-get install ipxe
    Fedora 21/RHEL7/CentOS7:
        yum install ipxe-bootimgs
    Fedora 22 or higher:
        dnf install ipxe-bootimgs
  5. Copy the iPXE boot image (undionly.kpxe for BIOS and ipxe.efi for UEFI) to /tftpboot. The binary might be found at:

        cp /usr/lib/ipxe/{undionly.kpxe,ipxe.efi} /tftpboot
        cp /usr/share/ipxe/{undionly.kpxe,ipxe.efi} /tftpboot


    If the packaged version of the iPXE boot image doesn’t work, you can download a prebuilt one from or build one image from source, see for more information.

  6. Enable/Configure iPXE in the Bare Metal Service’s configuration file (/etc/ironic/ironic.conf):

    # Enable iPXE boot. (boolean value)
    # Neutron bootfile DHCP parameter. (string value)
    # Bootfile DHCP parameter for UEFI boot mode. (string value)
    # Template file for PXE configuration. (string value)
    # Template file for PXE configuration for UEFI boot loader.
    # (string value)
  7. It is possible to configure the Bare Metal service in such a way that nodes will boot into the deploy image directly from Object Storage. Doing this avoids having to cache the images on the ironic-conductor host and serving them via the ironic-conductor’s HTTP server. This can be done if:

    1. the Image Service is used for image storage;
    2. the images in the Image Service are internally stored in Object Storage;
    3. the Object Storage supports generating temporary URLs for accessing objects stored in it. Both the OpenStack Swift and RADOS Gateway provide support for this.

    Configure this by setting the [pxe]/ipxe_use_swift configuration option to True as follows:

    # Download deploy images directly from swift using temporary
    # URLs. If set to false (default), images are downloaded to
    # the ironic-conductor node and served over its local HTTP
    # server. Applicable only when 'ipxe_enabled' option is set to
    # true. (boolean value)

    Although the HTTP server still has to be deployed and configured (as it will serve iPXE boot script and boot configuration files for nodes), such configuration will shift some load from ironic-conductor hosts to the Object Storage service which can be scaled horizontally.

    Note that when SSL is enabled on the Object Storage service you have to ensure that iPXE firmware on the nodes can indeed boot from generated temporary URLs that use HTTPS protocol.

  8. Restart the ironic-conductor process:

      sudo systemctl restart openstack-ironic-conductor
      sudo service ironic-conductor restart

PXE multi-architecture setup

It is possible to deploy servers of different architecture by one conductor. To use this feature, architecture-specific boot and template files must be configured using the configuration options [pxe]pxe_bootfile_name_by_arch and [pxe]pxe_config_template_by_arch respectively, in the Bare Metal service’s configuration file (/etc/ironic/ironic.conf).

These two options are dictionary values; the key is the architecture and the value is the boot (or config template) file. A node’s cpu_arch property is used as the key to get the appropriate boot file and template file. If the node’s cpu_arch is not in the dictionary, the configuration options (in [pxe] group) pxe_bootfile_name, pxe_config_template, uefi_pxe_bootfile_name and uefi_pxe_config_template will be used instead.

In the following example, since ‘x86’ and ‘x86_64’ keys are not in the pxe_bootfile_name_by_arch or pxe_config_template_by_arch options, x86 and x86_64 nodes will be deployed by ‘pxelinux.0’ or ‘bootx64.efi’, depending on the node’s boot_mode capability (‘bios’ or ‘uefi’). However, aarch64 nodes will be deployed by ‘grubaa64.efi’, and ppc64 nodes by ‘bootppc64’:


# Bootfile DHCP parameter. (string value)

# On ironic-conductor node, template file for PXE
# configuration. (string value)
pxe_config_template = $pybasedir/drivers/modules/pxe_config.template

# Bootfile DHCP parameter for UEFI boot mode. (string value)

# On ironic-conductor node, template file for PXE
# configuration for UEFI boot loader. (string value)

# Bootfile DHCP parameter per node architecture. (dict value)

# On ironic-conductor node, template file for PXE
# configuration per node architecture. For example:
# aarch64:/opt/share/grubaa64_pxe_config.template (dict value)

Networking service configuration

DHCP requests from iPXE need to have a DHCP tag called ipxe, in order for the DHCP server to tell the client to get the boot.ipxe script via HTTP. Otherwise, if the tag isn’t there, the DHCP server will tell the DHCP client to chainload the iPXE image (undionly.kpxe). The Networking service needs to be configured to create this DHCP tag, since it isn’t created by default.

  1. Create a custom dnsmasq.conf file with a setting for the ipxe tag. For example, create the file /etc/dnsmasq-ironic.conf with the content:

    # Create the "ipxe" tag if request comes from iPXE user class
    # Alternatively, create the "ipxe" tag if request comes from DHCP option 175
    # dhcp-match=set:ipxe,175
  2. In the Networking service DHCP Agent configuration file (typically located at /etc/neutron/dhcp_agent.ini), set the custom /etc/dnsmasq-ironic.conf file as the dnsmasq configuration file:

    dnsmasq_config_file = /etc/dnsmasq-ironic.conf
  3. Restart the neutron-dhcp-agent process:

    service neutron-dhcp-agent restart

IPMI support

If using the IPMITool driver, the ipmitool command must be present on the service node(s) where ironic-conductor is running. On most distros, this is provided as part of the ipmitool package. Source code is available at

Note that certain distros, notably Mac OS X and SLES, install openipmi instead of ipmitool by default. THIS DRIVER IS NOT COMPATIBLE WITH openipmi AS IT RELIES ON ERROR HANDLING OPTIONS NOT PROVIDED BY THIS TOOL.

Check that you can connect to and authenticate with the IPMI controller in your bare metal server by using ipmitool:

ipmitool -I lanplus -H <ip-address> -U <username> -P <password> chassis power status

<ip-address> = The IP of the IPMI controller you want to access


  1. This is not the bare metal node’s main IP. The IPMI controller should have its own unique IP.
  2. In case the above command doesn’t return the power status of the bare metal server, check for these:
    • ipmitool is installed.
    • The IPMI controller on your bare metal server is turned on.
    • The IPMI controller credentials passed in the command are right.
    • The conductor node has a route to the IPMI controller. This can be checked by just pinging the IPMI controller IP from the conductor node.


If there are slow or unresponsive BMCs in the environment, the retry_timeout configuration option in the [ipmi] section may need to be lowered. The default is fairly conservative, as setting this timeout too low can cause older BMCs to crash and require a hard-reset.

Bare Metal service supports sending IPMI sensor data to Telemetry with pxe_ipmitool, pxe_ipminative, agent_ipmitool, agent_pyghmi, agent_ilo, iscsi_ilo, pxe_ilo, and with pxe_irmc driver starting from Kilo release. By default, support for sending IPMI sensor data to Telemetry is disabled. If you want to enable it, you should make the following two changes in ironic.conf:

  • notification_driver = messaging in the DEFAULT section
  • send_sensor_data = true in the conductor section

If you want to customize the sensor types which will be sent to Telemetry, change the send_sensor_data_types option. For example, the below settings will send temperature, fan, voltage and these three sensor types of data to Telemetry:

  • send_sensor_data_types=Temperature,Fan,Voltage

If we use default value ‘All’ for all the sensor types which are supported by Telemetry, they are:

  • Temperature, Fan, Voltage, Current

Configure node web console

See Configuring Web or Serial Console.

Boot mode support

The following drivers support setting of boot mode (Legacy BIOS or UEFI).

  • pxe_ipmitool

The boot modes can be configured in Bare Metal service in the following way:

  • When no boot mode setting is provided, these drivers default the boot_mode to Legacy BIOS.

  • Only one boot mode (either uefi or bios) can be configured for the node.

  • If the operator wants a node to boot always in uefi mode or bios mode, then they may use capabilities parameter within properties field of an bare metal node. The operator must manually set the appropriate boot mode on the bare metal node.

    To configure a node in uefi mode, then set capabilities as below:

    ironic node-update <node-uuid> add properties/capabilities='boot_mode:uefi'

    Nodes having boot_mode set to uefi may be requested by adding an extra_spec to the Compute service flavor:

    nova flavor-key ironic-test-3 set capabilities:boot_mode="uefi"
    nova boot --flavor ironic-test-3 --image test-image instance-1

    If capabilities is used in extra_spec as above, nova scheduler (ComputeCapabilitiesFilter) will match only bare metal nodes which have the boot_mode set appropriately in properties/capabilities. It will filter out rest of the nodes.

    The above facility for matching in the Compute service can be used in heterogeneous environments where there is a mix of uefi and bios machines, and operator wants to provide a choice to the user regarding boot modes. If the flavor doesn’t contain boot_mode and boot_mode is configured for bare metal nodes, then nova scheduler will consider all nodes and user may get either bios or uefi machine.

Choosing the disk label


The term disk label is historically used in Ironic and was taken from parted. Apparently everyone seems to have a different word for disk label - these are all the same thing: disk type, partition table, partition map and so on...

Ironic allows operators to choose which disk label they want their bare metal node to be deployed with when Ironic is responsible for partitioning the disk; therefore choosing the disk label does not apply when the image being deployed is a whole disk image.

There are some edge cases where someone may want to choose a specific disk label for the images being deployed, including but not limited to:

  • For machines in bios boot mode with disks larger than 2 terabytes it’s recommended to use a gpt disk label. That’s because a capacity beyond 2 terabytes is not addressable by using the MBR partitioning type. But, although GPT claims to be backward compatible with legacy BIOS systems that’s not always the case.
  • Operators may want to force the partitioning to be always MBR (even if the machine is deployed with boot mode uefi) to avoid breakage of applications and tools running on those instances.

The disk label can be configured in two ways; when Ironic is used with the Compute service or in standalone mode. The following bullet points and sections will describe both methods:

  • When no disk label is provided Ironic will configure it according to the boot mode; bios boot mode will use msdos and uefi boot mode will use gpt.
  • Only one disk label - either msdos or gpt - can be configured for the node.

When used with Compute service

When Ironic is used with the Compute service the disk label should be set to node’s properties/capabilities field and also to the flavor which will request such capability, for example:

ironic node-update <node-uuid> add properties/capabilities='disk_label:gpt'

As for the flavor:

nova flavor-key baremetal set capabilities:disk_label="gpt"

When used in standalone mode

When used without the Compute service, the disk label should be set directly to the node’s instance_info field, as below:

ironic node-update <node-uuid> add instance_info/capabilities='{"disk_label": "gpt"}'
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