ironic/doc/source/admin/drivers/pxe.rst

Configuring PXE boot interface

Enable persistent boot device for deploy/clean operation

Ironic uses non-persistent boot for cleaning/deploying phases as default, in PXE interface. For some drivers, a persistent change is far more costly than a non-persistent one, so this can bring performance improvements.

Enable persistent boot device on node

1. Set the flag force_persistent_boot_device to True in the node's driver_info:

   $ openstack baremetal node set --driver-info force_persistent_boot_device=True <node>

   Note

   It's recommended to check if the node's state has not changed as there is no way of locking the node between these commands.

Once the flag is present, the next cleaning and deploy steps will be done with persistent boot for that node.