Creating an instance using images_type=lvm fails on ephemeral volume creation

[dinu]

Steps to reproduce:

# grep -B1 images /etc/nova/nova.conf
[libvirt]
images_type = lvm
images_volume_group = vgroot

# nova boot --flavor <flavor id> --image <image_id> --key-name id_rsa_test --security-groups default --nic net-id=<net_id> test

Expected result: instance will boot
Actual result: instance spawn fail.

Resulting /var/log/nova/nova-compute.log (on hypervisor)

Aug 4 22:06:32 ubuntu nova-compute[10477]: 2016-08-04 22:06:32.294 10477 ERROR nova.compute.manager [req-d3efb66e-b216-4944-9b61-a0afeb82048e 93c084ec050a4ffc828883d7dbba9dc6 0b01b979930c47369f5933ef06abb768 - - -] [instance: 596d8647-4093-4e29-aac9-51d986d34e68] Instance failed to spawn
Aug 4 22:06:32 ubuntu nova-compute[10477]: 2016-08-04 22:06:32.294 10477 ERROR nova.compute.manager [instance: 596d8647-4093-4e29-aac9-51d986d34e68] Traceback (most recent call last):
Aug 4 22:06:32 ubuntu nova-compute[10477]: 2016-08-04 22:06:32.294 10477 ERROR nova.compute.manager [instance: 596d8647-4093-4e29-aac9-51d986d34e68] File "/usr/lib/python2.7/dist-packages/nova/compute/manager.py", line 2218, in _build_resources
Aug 4 22:06:32 ubuntu nova-compute[10477]: 2016-08-04 22:06:32.294 10477 ERROR nova.compute.manager [instance: 596d8647-4093-4e29-aac9-51d986d34e68] yield resources
Aug 4 22:06:32 ubuntu nova-compute[10477]: 2016-08-04 22:06:32.294 10477 ERROR nova.compute.manager [instance: 596d8647-4093-4e29-aac9-51d986d34e68] File "/usr/lib/python2.7/dist-packages/nova/compute/manager.py", line 2064, in _build_and_run_instance
Aug 4 22:06:32 ubuntu nova-compute[10477]: 2016-08-04 22:06:32.294 10477 ERROR nova.compute.manager [instance: 596d8647-4093-4e29-aac9-51d986d34e68] block_device_info=block_device_info)
Aug 4 22:06:32 ubuntu nova-compute[10477]: 2016-08-04 22:06:32.294 10477 ERROR nova.compute.manager [instance: 596d8647-4093-4e29-aac9-51d986d34e68] File "/usr/lib/python2.7/dist-packages/nova/virt/libvirt/driver.py", line 2761, in spawn
Aug 4 22:06:32 ubuntu nova-compute[10477]: 2016-08-04 22:06:32.294 10477 ERROR nova.compute.manager [instance: 596d8647-4093-4e29-aac9-51d986d34e68] admin_pass=admin_password)
Aug 4 22:06:32 ubuntu nova-compute[10477]: 2016-08-04 22:06:32.294 10477 ERROR nova.compute.manager [instance: 596d8647-4093-4e29-aac9-51d986d34e68] File "/usr/lib/python2.7/dist-packages/nova/virt/libvirt/driver.py", line 3201, in _create_image
Aug 4 22:06:32 ubuntu nova-compute[10477]: 2016-08-04 22:06:32.294 10477 ERROR nova.compute.manager [instance: 596d8647-4093-4e29-aac9-51d986d34e68] ephemeral_size=ephemeral_gb)
Aug 4 22:06:32 ubuntu nova-compute[10477]: 2016-08-04 22:06:32.294 10477 ERROR nova.compute.manager [instance: 596d8647-4093-4e29-aac9-51d986d34e68] File "/usr/lib/python2.7/dist-packages/nova/virt/libvirt/imagebackend.py", line 254, in cache
Aug 4 22:06:32 ubuntu nova-compute[10477]: 2016-08-04 22:06:32.294 10477 ERROR nova.compute.manager [instance: 596d8647-4093-4e29-aac9-51d986d34e68] if size > self.get_disk_size(base):
Aug 4 22:06:32 ubuntu nova-compute[10477]: 2016-08-04 22:06:32.294 10477 ERROR nova.compute.manager [instance: 596d8647-4093-4e29-aac9-51d986d34e68] File "/usr/lib/python2.7/dist-packages/nova/virt/libvirt/imagebackend.py", line 308, in get_disk_size
Aug 4 22:06:32 ubuntu nova-compute[10477]: 2016-08-04 22:06:32.294 10477 ERROR nova.compute.manager [instance: 596d8647-4093-4e29-aac9-51d986d34e68] return disk.get_disk_size(name)
Aug 4 22:06:32 ubuntu nova-compute[10477]: 2016-08-04 22:06:32.294 10477 ERROR nova.compute.manager [instance: 596d8647-4093-4e29-aac9-51d986d34e68] File "/usr/lib/python2.7/dist-packages/nova/virt/disk/api.py", line 147, in get_disk_size
Aug 4 22:06:32 ubuntu nova-compute[10477]: 2016-08-04 22:06:32.294 10477 ERROR nova.compute.manager [instance: 596d8647-4093-4e29-aac9-51d986d34e68] return images.qemu_img_info(path).virtual_size
Aug 4 22:06:32 ubuntu nova-compute[10477]: 2016-08-04 22:06:32.294 10477 ERROR nova.compute.manager [instance: 596d8647-4093-4e29-aac9-51d986d34e68] File "/usr/lib/python2.7/dist-packages/nova/virt/images.py", line 50, in qemu_img_info
Aug 4 22:06:32 ubuntu nova-compute[10477]: 2016-08-04 22:06:32.294 10477 ERROR nova.compute.manager [instance: 596d8647-4093-4e29-aac9-51d986d34e68] raise exception.DiskNotFound(location=path)
Aug 4 22:06:32 ubuntu nova-compute[10477]: 2016-08-04 22:06:32.294 10477 ERROR nova.compute.manager [instance: 596d8647-4093-4e29-aac9-51d986d34e68] DiskNotFound: No disk at /var/lib/nova/instances/_base/ephemeral_5_40d1d2c
Aug 4 22:06:32 ubuntu nova-compute[10477]: 2016-08-04 22:06:32.294 10477 ERROR nova.compute.manager [instance: 596d8647-4093-4e29-aac9-51d986d34e68]
Aug 4 22:06:32 ubuntu nova-compute[10477]: 2016-08-04 22:06:32.295 10477 INFO nova.compute.manager [req-d3efb66e-b216-4944-9b61-a0afeb82048e 93c084ec050a4ffc828883d7dbba9dc6 0b01b979930c47369f5933ef06abb768 - - -] [instance: 596d8647-4093-4e29-aac9-51d986d34e68] Terminating instance
Aug 4 22:06:32 ubuntu nova-compute[10477]: 2016-08-04 22:06:32.297 10477 DEBUG nova.compute.manager [req-d3efb66e-b216-4944-9b61-a0afeb82048e 93c084ec050a4ffc828883d7dbba9dc6 0b01b979930c47369f5933ef06abb768 - - -] [instance: 596d8647-4093-4e29-aac9-51d986d34e68] Start destroying the instance on the hypervisor. _shutdown_instance /usr/lib/python2.7/dist-packages/nova/compute/manager.py:2330

Workaround: # touch /var/lib/nova/instances/_base/ephemeral_5_40d1d2c
on the hypervisor will address the issue and allow the instance to start.

Additional info:

# nova flavor-show c2-r4-d5
+----------------------------+--------------------------------------+
| Property | Value |
+----------------------------+--------------------------------------+
| OS-FLV-DISABLED:disabled | False |
| OS-FLV-EXT-DATA:ephemeral | 5 |
| disk | 10 |
| extra_specs | {} |
| id | 106ab90e-dfd0-4bbf-a232-cfaee5a34cc6 |
| name | c2-r4-d5 |
| os-flavor-access:is_public | True |
| ram | 4096 |
| rxtx_factor | 1.0 |
| swap | 2048 |
| vcpus | 2 |
+----------------------------+--------------------------------------+

Hypervisor host:
# uname -a
Linux enc01-c03 4.4.0-31-generic #50-Ubuntu SMP Wed Jul 13 00:07:12 UTC 2016 x86_64 x86_64 x86_64 GNU/Linux
# lsb_release -sc
xenial

# dpkg -l | grep nova
ii nova-common 2:13.0.0-0ubuntu5 all OpenStack Compute - common files
ii nova-compute 2:13.0.0-0ubuntu5 all OpenStack Compute - compute node base
ii nova-compute-kvm 2:13.0.0-0ubuntu5 all OpenStack Compute - compute node (KVM)
ii nova-compute-libvirt 2:13.0.0-0ubuntu5 all OpenStack Compute - compute node libvirt support
ii python-nova 2:13.0.0-0ubuntu5 all OpenStack Compute Python libraries
ii python-novaclient 2:3.3.1-2 all client library for OpenStack Compute API - Python 2.7

# vgdisplay
  --- Volume group ---
  VG Name vgroot
  System ID
  Format lvm2
  Metadata Areas 1
  Metadata Sequence No 82
  VG Access read/write
  VG Status resizable
  MAX LV 0
  Cur LV 2
  Open LV 2
  Max PV 0
  Cur PV 1
  Act PV 1
  VG Size 68.32 GiB
  PE Size 4.00 MiB
  Total PE 17491
  Alloc PE / Size 10841 / 42.35 GiB
  Free PE / Size 6650 / 25.98 GiB
  VG UUID eNzdGr-0g5b-YDyE-myxL-AdCR-g94Q-G5eUSR

[Dr. Jens Harbott (j-harbott)]

This looks to me like a duplicate of https://bugs.launchpad.net/nova/+bug/1608934 , can you check whether applying https://review.openstack.org/355415 fixes the issue for you?

[dinu (dinu-arateanu)]

https://review.openstack.org/355415 appears to fix the issue indeed. Both the root and ephemeral LVM volumes are created correctly.