Volume-backed instances with config-drive=true fail to live-migrate

[Anna Babich]

Upstream bug: https://bugs.launchpad.net/nova/+bug/1589457

Reproduced on env (1 Controller, 2 Computes , 1 Cinder LVM node):
shotgun2 short-report
cat /etc/fuel_build_id:
 443
cat /etc/fuel_build_number:
 443
cat /etc/fuel_release:
 9.0
cat /etc/fuel_openstack_version:
 mitaka-9.0
rpm -qa | egrep 'fuel|astute|network-checker|nailgun|packetary|shotgun':
 fuel-release-9.0.0-1.mos6347.noarch
 fuel-provisioning-scripts-9.0.0-1.mos8723.noarch
 fuel-bootstrap-cli-9.0.0-1.mos284.noarch
 fuel-migrate-9.0.0-1.mos8430.noarch
 rubygem-astute-9.0.0-1.mos748.noarch
 network-checker-9.0.0-1.mos73.x86_64
 fuel-mirror-9.0.0-1.mos137.noarch
 fuel-openstack-metadata-9.0.0-1.mos8723.noarch
 fuel-notify-9.0.0-1.mos8430.noarch
 nailgun-mcagents-9.0.0-1.mos748.noarch
 python-fuelclient-9.0.0-1.mos319.noarch
 fuelmenu-9.0.0-1.mos271.noarch
 fuel-9.0.0-1.mos6347.noarch
 fuel-utils-9.0.0-1.mos8430.noarch
 fuel-setup-9.0.0-1.mos6347.noarch
 fuel-misc-9.0.0-1.mos8430.noarch
 fuel-library9.0-9.0.0-1.mos8430.noarch
 shotgun-9.0.0-1.mos90.noarch
 fuel-agent-9.0.0-1.mos284.noarch
 fuel-ui-9.0.0-1.mos2714.noarch
 fuel-ostf-9.0.0-1.mos934.noarch
 python-packetary-9.0.0-1.mos137.noarch
 fuel-nailgun-9.0.0-1.mos8723.noarch
[root@nailgun ~]#

Steps to reproduce:
1) Create a bootable volume from an image
2) Boot an instance from created volume
3) Try to live migrate the booted volume-baked instance

Expected result: live migration is successful
Actual result:
BadRequest: node-3.test.domain.local is not on shared storage: Live migration can not be used without shared storage except a booted from volume VM which does not have a local disk.

[Timur Nurlygayanov (tnurlygayanov)]

is it default configuration / default live migration workflow? Please change the priority to critical if all users are affected by the issue.

[Timofey Durakov (tdurakov)]

Libvirt prior to version 1.2.17 doesn't allow block-migration of instances with attached volumes and true live-migration of instances with config drive located on non local-storage both.
This patch changed default config for nova to enable config_drives by default(closes 2 bugs, and 2 related bugs mentioned): https://review.openstack.org/#/c/322132/ At this point it's not possible to fix these issues without changing force_config_drive param in nova. MOS Operator has several possibilities to retain live-migration of volume-backed instances:
- set force_config_drive to True in nova.conf and restart services before booting instance.
- use ceph for ephemerals or set up file-base local storage(e.g. NFS)
- upgrade libvirt to 1.2.17
These options should be mentioned in release notes.
For 10.0 MOS will use Ubuntu 16.04 which ships with libvirt 1.3.1 so it will be possible to use block-migration.

[Timur Nurlygayanov (tnurlygayanov)]

Ok, this bug can't be fixed in 9.0 release, assigned to doc team to add release notes about the issue and possible workarounds.

Doc team, could you please use comment #2 as a reference for the release notes about the issue?

Thank you!

[Timofey Durakov (tdurakov)]

As noticed by @ababich, there is typo in a list of workarounds:
operator should set force_config_drive to False in nova.conf and restart services before booting instance.

[Fuel Devops McRobotson (fuel-devops-robot)]

Related fix proposed to branch: master
Change author: Olena Logvinova <email address hidden>
Review: https://review.fuel-infra.org/21971

[Fuel Devops McRobotson (fuel-devops-robot)]

Reviewed: https://review.fuel-infra.org/21971
Submitter: Evgeny Konstantinov <email address hidden>
Branch: master

Commit: 55e64d28576f50fe34272e34d72aeb3f409d45b7
Author: Olena Logvinova <email address hidden>
Date: Tue Jun 14 09:12:37 2016

[RN9] Nova known issue - LP1589460

This patch adds a new Nova known issue with its workarounds
to the 'Known issues' section of RN 9.0 page.

Change-Id: I2779d78edee5eaddb7646388a0568f53fdab5c89
Closes-Bug: #1589460

[Olena Logvinova (ologvinova)]

RN is published here: https://docs.mirantis.com/openstack/fuel/fuel-master/release-notes.html#mos-known-issues