Ironic¶
Introduction¶
The ironic hypervisor driver wraps the Bare Metal (ironic) API, enabling Nova to provision baremetal resources using the same user-facing API as for server management.
This is the only driver in nova where one compute service can map to many
hosts, meaning a nova-compute
service can manage multiple ComputeNodes
.
An ironic driver managed compute service uses the ironic node uuid
for the
compute node hypervisor_hostname
(nodename) and uuid
fields. The
relationship of instance:compute node:ironic node
is 1:1:1.
Scheduling of bare metal nodes is based on custom resource classes, specified
via the resource_class
property on a node and a corresponding resource
property on a flavor (see the flavor documentation).
The RAM and CPU settings on a flavor are ignored, and the disk is only used to
determine the root partition size when a partition image is used (see the
image documentation).
Configuration¶
Scaling and performance issues¶
The
update_available_resource
periodic task reports all the resources managed by Ironic. Depending the number of nodes, it can take a lot of time. The nova-compute will not perform any other operations when this task is running. You can use conductor groups to help scale, by settingironic.partition_key
.
Known limitations / Missing features¶
Migrate
Resize
Snapshot
Pause
Shelve
Evacuate