nova don't create local disk if specify device=vda in block_device_mapping_v2

[Eli Qiao]

I wish to create a instance with local disk(1G) and attaching a blank(new created) volume(2G).

using follow nova command line api, but I specify the bdm's device=vda

nova --debug boot --image baaece45-58a2-4e4c-b8b7-7b3f12fe4bc6 --flavor 1 --nic net-id=9af3d913-dd65-4864-88b5-cd42bce3f672 --block-device source=blank,dest=volume,device=vda,size=2 test12

I got a instance , by checking domain xml
I only got 1 block device(2G), but no local disk was created.

============
expect result.
1. raise badrequest if sepcify device=vda in block-device.
or
2. just ignore device=vda in block-device and create 2 device for this instance.

I prefer option 1.

[jichenjc (jichenjc)]

+-----+-----------+-----------+------+-----------+------+-------+-------------+-----------+
| ID | Name | Memory_MB | Disk | Ephemeral | Swap | VCPUs | RXTX_Factor | Is_Public |
+-----+-----------+-----------+------+-----------+------+-------+-------------+-----------+
| 1 | m1.tiny | 512 | 1 | 0 | | 1 | 1.0 | True |

if flavor 1 this ? why need 2 devices ? no ephemeral , no swap disk?

[Eli Qiao (taget-9)]

yes, it is.

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/180457

[OpenStack Infra (hudson-openstack)]

Change abandoned by Eli Qiao (<email address hidden>) on branch: master
Review: https://review.openstack.org/180457
Reason: merged changes to https://review.openstack.org/#/c/171984

[OpenStack Infra (hudson-openstack)]

Change abandoned by Michael Still (<email address hidden>) on branch: master
Review: https://review.openstack.org/171984
Reason: This patch has been sitting unchanged for more than 12 weeks. I am therefore going to abandon it to keep the nova review queue sane. Please feel free to restore the change if you're still working on it.

[OpenStack Infra (hudson-openstack)]

Change abandoned by Stephen Finucane (<email address hidden>) on branch: master
Review: https://review.opendev.org/171984