8fc538bdd9
This file belongs to classic drivers and is not used anymore, the reference link in the admin/interfaces/boot.rst is marked hidden, thus can be removed. Change-Id: Iefe656a4a79491f5f0513ab4e315b2da08918355
65 lines
2.6 KiB
ReStructuredText
65 lines
2.6 KiB
ReStructuredText
===============
|
|
Boot interfaces
|
|
===============
|
|
|
|
The boot interface manages booting of both the deploy ramdisk and the user
|
|
instances on the bare metal node.
|
|
|
|
The `PXE boot`_ interface is generic and works with all hardware that supports
|
|
booting from network. Alternatively, several vendors provide *virtual media*
|
|
implementations of the boot interface. They work by pushing an ISO image to
|
|
the node's `management controller`_, and do not require either PXE or iPXE.
|
|
Check your driver documentation at :doc:`../drivers` for details.
|
|
|
|
.. _pxe-boot:
|
|
|
|
PXE boot
|
|
--------
|
|
|
|
The ``pxe`` boot interface uses PXE_ or iPXE_ to deliver the target
|
|
kernel/ramdisk pair. PXE uses relatively slow and unreliable TFTP protocol
|
|
for transfer, while iPXE uses HTTP. The downside of iPXE is that it's less
|
|
common, and usually requires bootstrapping using PXE first.
|
|
|
|
The ``pxe`` boot interface works by preparing a PXE/iPXE environment for a
|
|
node on the file system, then instructing the DHCP provider (for example,
|
|
the Networking service) to boot the node from it. See
|
|
:ref:`iscsi-deploy-example` and :ref:`direct-deploy-example` for a better
|
|
understanding of the whole deployment process.
|
|
|
|
.. note::
|
|
Both PXE and iPXE are configured differently, when UEFI boot is used
|
|
instead of conventional BIOS boot. This is particularly important for CPU
|
|
architectures that do not have BIOS support at all.
|
|
|
|
The ``pxe`` boot interface is used by default for many hardware types,
|
|
including ``ipmi``. Some hardware types, notably ``ilo`` and ``irmc`` have their
|
|
specific implementations of the PXE boot interface.
|
|
|
|
Additional configuration is required for this boot interface - see
|
|
:doc:`/install/configure-pxe` for details.
|
|
|
|
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.
|
|
|
|
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.
|
|
|
|
|
|
.. _PXE: https://en.wikipedia.org/wiki/Preboot_Execution_Environment
|
|
.. _iPXE: https://en.wikipedia.org/wiki/IPXE
|
|
.. _management controller: https://en.wikipedia.org/wiki/Out-of-band_management
|