f02ef8ad7a
First, "Enabling Drivers" is a really confusing title, since this page links to complete driver documentation. It also links to IPA docs and the PXE driver interface. Next, our documentation is full of remarks about e.g. "pxe_* family of drivers", which are misleading in the presence of hardware types and the pxe_agent_cimc driver. We also have mentions of "iscsi deploy method" without detailed explanation of how this method relates to hardware types and classic drivers. This change consolidates drivers and interfaces documentation under the more clearly named root page. A new page is created with sections for both deploy interfaces to use for linking from wherever a link to a particular deploy interface is required. Change-Id: Ifb8328ccaaac443fac276873e2c375ebcf983f03
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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 ../drivers for details.
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 iscsi-deploy-example and 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, and for all classic drivers
with names starting with pxe_. 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
/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.
../drivers/pxe