From e25c6e23b466c24f78ddec7e6321bf33ac73743f Mon Sep 17 00:00:00 2001 From: Julia Kreger Date: Tue, 24 Jul 2018 10:13:51 -0700 Subject: [PATCH] Ramdisk deploy driver doc Docs for the ramdisk driver, at least at a basic level. Change-Id: Ie5f829fa6789f8a3e09eb1c9454f79b4315ae95a Task: #23164 Story: #1753842 --- doc/source/admin/interfaces/deploy.rst | 52 ++++++++++++++++++++++++++ 1 file changed, 52 insertions(+) diff --git a/doc/source/admin/interfaces/deploy.rst b/doc/source/admin/interfaces/deploy.rst index fd5d8bc9f0..676ce65262 100644 --- a/doc/source/admin/interfaces/deploy.rst +++ b/doc/source/admin/interfaces/deploy.rst @@ -91,3 +91,55 @@ it, see :doc:`Ansible deploy interface <../drivers/ansible>`. :hidden: ../drivers/ansible + +Ramdisk deploy +============== + +The ramdisk interface is intended to provide a mechanism to "deploy" an +instance where the item to be deployed is in reality a ramdisk. +Most commonly this is peformed when an instance is booted via PXE or iPXE, +with the only local storage contents being those in memory. Initially this +is only supported by the ``pxe`` boot interface, but other boot interfaces +could support this funtionality in the future. + +As with most non-default interfaces, it must be enabled and set for a node +to be utilized: + +.. code-block:: ini + + [DEFAULT] + ... + enabled_deploy_interfaces = iscsi,direct,ramdisk + ... + +Once enabled and the conductor(s) have been restarted, the interface can +be set upon creation of a new node or update a pre-existing node: + +.. code-block:: shell + + openstack baremetal node create --driver ipmi \ + --deploy-interface ramdisk \ + --boot-interface pxe + openstack baremetal node set --deploy-interface ramdisk + +The intended use case is for advanced scientific and ephemeral workloads +where the step of writing an image to the local storage is not required +or desired. As such, this interface does come with several caveats: + +* Configuration drives are not supported. +* Disk image contents are not written to the bare metal node. +* Users and Operators who intend to leverage this interface should + expect to leverage a metadata service, custom ramdisk images, or the + ``instance_info/ramdisk_kernel_arguments`` parameter to add options to + the kernel boot command line. +* Bare metal nodes must continue to have network access to PXE and iPXE + network resources. This is contrary to most tenant networking enabled + configurations where this access is restricted to the provisioning and + cleaning networks +* As with all deployment interfaces, automatic cleaning of the node will + still occur with the contents of any local storage being wiped between + deployments. + +.. warning:: + As of the Rocky release of the BareMetal service, only the ``pxe`` boot + interface is supported.