Root device hints

Registered by Lucas Alvares Gomes on 2014-12-03

Allow passing hints to Ironic to decide which device should be selected for the deployment.

When the deploy ramdisk boots Ironic picks the first disk it finds to be the root device (the device where the image will be put on). If the serverhas more than one SATA, SCSI or IDE disk controller, the order in which their corresponding device nodes are added is arbitrary[1][2]. This may result in devices like /dev/sda and /dev/sdb switching around on each boot and Ironic picking different disk every time the machine is being deployed.

[1] https://wiki.archlinux.org/index.php/persistent_block_device_naming
[2] https://access.redhat.com/documentation/en-US/Red_Hat_Enterprise_Linux/5/html/Online_Storage_Reconfiguration_Guide/persistent_naming.html

Blueprint information

Status:
Complete
Approver:
devananda
Priority:
High
Drafter:
Lucas Alvares Gomes
Direction:
Approved
Assignee:
Lucas Alvares Gomes
Definition:
Approved
Series goal:
Accepted for kilo
Implementation:
Implemented
Milestone target:
milestone icon 2015.1.0
Started by
devananda on 2015-02-23
Completed by
John Stafford on 2015-03-17

Related branches

Sprints

Whiteboard

Gerrit topic: https://review.openstack.org/#q,topic:bp/root-device-hints,n,z

Addressed by: https://review.openstack.org/138729
    Root device hints

Addressed by: https://review.openstack.org/137762
    Extend API multivalue fields

Addressed by: https://review.openstack.org/142109
    PXE: Pass root device hints via kernel cmdline

Gerrit topic: https://review.openstack.org/#q,topic:root-device-hints,n,z

Addressed by: https://review.openstack.org/163079
    Add support for root device hints

Addressed by: https://review.openstack.org/163078
    Move _get_agent_params() to a common place

Addressed by: https://review.openstack.org/163794
    Add validate for root device hints

Addressed by: https://review.openstack.org/163857
    IPA: Add support for root device hints

---------
diskimage-builder change which has not landed

Addressed by: https://review.openstack.org/142178
    Ironic: Deploy ramdisk to find the right root device

Addressed by: https://review.openstack.org/166801
    Add root device hints documentation

(?)

Work Items

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