ironic/doc/source/install/configure-nova-flavors.rst

Create flavors for use with the Bare Metal service

Scheduling based on properties

You'll need to create a special bare metal flavor in the Compute service. The flavor is mapped to the bare metal node through the hardware specifications.

1. Change these to match your hardware:

   $ RAM_MB=1024
   $ CPU=2
   $ DISK_GB=100
   $ ARCH={i686|x86_64}

2. Create the bare metal flavor by executing the following command:

   $ nova flavor-create my-baremetal-flavor auto $RAM_MB $DISK_GB $CPU

   Note

   You can replace auto with your own flavor id.

3. Set the architecture as extra_specs information of the flavor. This will be used to match against the properties of bare metal nodes:

   $ nova flavor-key my-baremetal-flavor set cpu_arch=$ARCH

Scheduling based on resource classes

The Newton release of the Bare Metal service includes a field on the node resource called resource_class. This field is available in version 1.21 of the Bare Metal service API. Starting with the Pike release, this field has to be populated for all nodes, as explained in enrollment.

As of the Pike release, a Compute service flavor is able to use this field for scheduling, instead of the CPU, RAM, and disk properties defined in the flavor above. A flavor can request exactly one instance of a bare metal resource class.

To achieve that, the flavors, created as described in Scheduling based on properties, have to be associated with one custom resource class each. A name of the custom resource class is the name of node's resource class, but upper-cased, with CUSTOM_ prefix prepended, and all punctuation replaced with an underscore:

$ nova flavor-key my-baremetal-flavor set resources:CUSTOM_<RESOURCE_CLASS>=1

Another set of flavor properties should be used to disable scheduling based on standard properties for a bare metal flavor:

$ nova flavor-key my-baremetal-flavor set resources:VCPU=0
$ nova flavor-key my-baremetal-flavor set resources:MEMORY_MB=0
$ nova flavor-key my-baremetal-flavor set resources:DISK_GB=0

Warning

The last step will be mandatory in the Queens release, as the Compute service will stop providing standard resources for bare metal nodes.

Example

If you want to define a class of nodes called baremetal.with-GPU, start with tagging some nodes with it:

$ ironic --ironic-api-version=1.21 node-update $NODE_UUID \
  replace resource_class=baremetal.with-GPU

Warning

It is possible to add a resource class to active nodes, but it is not possiblre to replace an existing resource class on them.

Then you can update your flavor to request the resource class instead of the standard properties:

$ nova flavor-key my-baremetal-flavor set resources:CUSTOM_BAREMETAL_WITH_GPU=1
$ nova flavor-key my-baremetal-flavor set resources:VCPU=0
$ nova flavor-key my-baremetal-flavor set resources:MEMORY_MB=0
$ nova flavor-key my-baremetal-flavor set resources:DISK_GB=0

Note how baremetal.with-GPU in the node's resource_class field becomes CUSTOM_BAREMETAL_WITH_GPU in the flavor's properties.