Fail to boot VM from image with one ephemeral disk

[Qin Zhao]

Kilo latest code

I attempt to boot a VM from qcow2 image, and also create one ephemeral disk, but my request is refused by nova-api.

[root@icm ~]# nova boot --flavor 1 --image cirros --ephemeral size=2 zhaoqin
ERROR (BadRequest): Block Device Mapping is Invalid: Boot sequence for the instance and image/block device mapping combination is not valid. (HTTP 400) (Request-ID: req-6e272b55-a20e-4e1c-9b76-c1fb9d232fa6)

The error is raised from _validate_bdm() in nova/compute/api.py. Since there is only one ephemeral disk in block_device_mapping_v2 list and its boot_index is -1, boot_indexes becomes an empty list. And the error is raised, because 0 is not in boot_indexes list:

        if 0 not in boot_indexes or not _subsequent_list(boot_indexes):
            raise exception.InvalidBDMBootSequence()

[jichenjc (jichenjc)]

well , not sure it's related to https://review.openstack.org/#/c/165932/
can you check whether your novaclient has the update?

--image should insert a boot index 0 record so this validation should pass

[Qin Zhao (zhaoqin)]

@Ji Chen, if I add the image to block_device_mapping_v2, I get a new error:

[root@icm ~]# curl -g -i -X POST http://10.104.0.30:8774/v2/a33ebeca3172404aad880a3d3996f66c/servers -H "User-Agent: python-novaclient" -H "Content-Type: application/json" -H "Accept: application/json" -H "X-Auth-Token: 7f33401505cd479a8d4c9a6480a54803" -d '{"server": {"name": "zhaoqin", "imageRef": "0e3af016-30bb-4b87-b0fc-f88e29744d05", "block_device_mapping_v2": [{"source_type": "image", "boot_index": 0, "delete_on_termination": true, "destination_type": "local", "uuid": "0e3af016-30bb-4b87-b0fc-f88e29744d05"}, {"source_type": "blank", "boot_index": -1, "delete_on_termination": true, "volume_size": "2", "destination_type": "local"}], "flavorRef": "1", "max_count": 1, "min_count": 1}}'
HTTP/1.1 400 Bad Request
Content-Length: 117
Content-Type: application/json; charset=UTF-8
X-Compute-Request-Id: req-658dacc8-d7fa-4d15-b9d4-c5d8ad4d7804
Date: Fri, 10 Apr 2015 14:38:34 GMT

{"badRequest": {"message": "Block Device Mapping is Invalid: Mapping image to local is not supported.", "code": 400}}

[Qin Zhao (zhaoqin)]

If our assumption is that block_device_mapping_v2 must contains one entry whose boot_index is 0, we will need an entry whose source type is image as I does in comment #2. However, api does not allow me to place this image disk on local drive.

What is the correct api request which can create a instance from image, place boot disk on local drive, and also create one ephemeral disk on local drive for this instance?

[Qin Zhao (zhaoqin)]

Thanks, Ji Chen. I feel https://review.openstack.org/#/c/166401/ should make it work. Let me have a test.

[Noel Nelson Dsouza (noelnelson)]

jichenjc (jichenjc) ,

I am not able to reproduce above bug.

My Environment
I am using Juno Version of Devstack.

Scenario I tried

stack@onecloud-Standard-PC-i440FX-PIIX-1996:~/devstack$ nova boot --image cirros-0.3.4-x86_64-uec --flavor 8 --ephemeral size=1 vm5
+--------------------------------------+----------------------------------------------------------------+
| Property | Value |
+--------------------------------------+----------------------------------------------------------------+
| OS-DCF:diskConfig | MANUAL |
| OS-EXT-AZ:availability_zone | nova |
| OS-EXT-SRV-ATTR:host | - |
| OS-EXT-SRV-ATTR:hypervisor_hostname | - |
| OS-EXT-SRV-ATTR:instance_name | instance-00000009 |
| OS-EXT-STS:power_state | 0 |
| OS-EXT-STS:task_state | scheduling |
| OS-EXT-STS:vm_state | building |
| OS-SRV-USG:launched_at | - |
| OS-SRV-USG:terminated_at | - |
| accessIPv4 | |
| accessIPv6 | |
| adminPass | m3dMTKpvpEUC |
| config_drive | |
| created | 2015-05-14T11:39:11Z |
| flavor | flv_5_root_2_eph_1_swap (8) |
| hostId | |
| id | 73c9401d-88bc-4d8a-830a-b41df5ac16f9 |
| image | cirros-0.3.4-x86_64-uec (b25c32d5-6c13-4c30-a36f-34e7f694446e) |
| key_name | - |
| metadata | {} |
| name | vm5 |
| os-extended-volumes:volumes_attached | [] |
| progress | 0 |
| security_groups | default ...

[BalaGopalaKrishna (bala-9)]

I've reproduces the isuue with kilo version.

stack@openstack:~/devstack$ nova boot --image cirros-0.3.2-x86_64-uec --flavor 1 --ephemeral size=1 VM1
ERROR (BadRequest): Block Device Mapping is Invalid: Boot sequence for the instance and image/block device mapping combination is not valid. (HTTP 400) (Request-ID: req-ae01afac-7770-4e28-a201-0bfb454d0091)

[BalaGopalaKrishna (bala-9)]

Thanks jichenjc, This bug is because of python-novaclient version difference

as you said we need to backport https://review.openstack.org/#/c/165932/ to stable/kilo to resolve this bug.

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: stable/kilo
Review: https://review.openstack.org/216401

[OpenStack Infra (hudson-openstack)]

Change abandoned by BalaGopalaKrishna (<email address hidden>) on branch: stable/kilo
Review: https://review.openstack.org/216401
Reason: I had sent another patch for the same.