Comment 0 for bug 1531241

After compute node re-installation Nova instance is running, but not accessible via network because DHCP client doesn't setup interfaces (see attached screenshot):

root@node-1:~# nova list
+--------------------------------------+--------------------+--------+------------+-------------+------------------------------------------------+
| ID | Name | Status | Task State | Power State | Networks |
+--------------------------------------+--------------------+--------+------------+-------------+------------------------------------------------+
| 50118e0e-e104-4cc0-b154-b0dcdaef0494 | test-serv818246635 | ACTIVE | - | Running | admin_internal_net=10.109.29.10, 10.109.28.132 |
+--------------------------------------+--------------------+--------+------------+-------------+------------------------------------------------+
root@node-1:~# ip netns
qrouter-36585fb6-089e-42ea-91cb-07785decd05e
qdhcp-d2486119-b310-41af-be67-9c52dec90277
haproxy
vrouter
root@node-1:~# ip netns exec qdhcp-d2486119-b310-41af-be67-9c52dec90277 ping -c 1 10.109.29.10
PING 10.109.29.10 (10.109.29.10) 56(84) bytes of data.

--- 10.109.29.10 ping statistics ---
1 packets transmitted, 0 received, 100% packet loss, time 0ms

root@node-1:~# ping -c 1 -W 1 10.109.28.132
PING 10.109.28.132 (10.109.28.132) 56(84) bytes of data.

--- 10.109.28.132 ping statistics ---
1 packets transmitted, 0 received, 100% packet loss, time 0ms

Steps to reproduce:

1. run auto test 'cinder_nova_partition_preservation' or manually follow its steps: https://github.com/openstack/fuel-qa/blob/77a672c3c6a37723a4d24d3db3260ab58661f518/fuelweb_test/tests/test_node_reinstallation.py#L463-L481

Expected result: test passed
Actual result: test fails with error "test-servNNNNNNN VM is not accessible via its FloatingIP"

There is only one error in nova-compute logs from snapshot:

http://paste.openstack.org/show/483057/

But after I reverted environment I got also these errors (see diagnostic_snapshot_after_revert.xz):

http://paste.openstack.org/show/483059/