One of our instances got stopped by nova on one of the compute nodes. We couldn't find any indication in the instance itself what causes this shutdown. Any idea what could trigger this?

OpenStack version is Icehouse.

Here the logs from nova:

2015-02-03 15:23:47.410 58450 WARNING nova.virt.libvirt.imagecache [-] Unknown base file: /var/lib/nova/instances/_base/7ff8a4ca1dc62785b8b510a72dffa7348a12c1c1

2015-02-03 16:03:48.336 58450 WARNING nova.virt.libvirt.imagecache [-] Unknown base file: /var/lib/nova/instances/_base/7ff8a4ca1dc62785b8b510a72dffa7348a12c1c1

2015-02-05 09:21:46.471 3945 INFO oslo.messaging._drivers.impl_qpid [-] Connected to AMQP server on mgmtserver:5672

2015-02-05 09:21:46.506 3945 INFO oslo.messaging._drivers.impl_qpid [-] Connected to AMQP server on mgmtserver:5672

2015-02-05 09:21:49.707 3945 INFO oslo.messaging._drivers.impl_qpid [-] Connected to AMQP server on mgmtserver:5672

2015-02-05 09:22:46.326 3945 WARNING nova.compute.manager [req-95612613-4588-4e3e-b999-7b18e5aa5c13 None None] Found 1 in the database and 0 on the hypervisor.

2015-02-05 09:22:46.518 3945 WARNING nova.compute.manager [req-95612613-4588-4e3e-b999-7b18e5aa5c13 None None] [instance: 411affdd-e836-4fe8-a16d-a9eda0152fda] Instance shutdown by itself. Calling the stop API.

2015-02-05 09:22:46.667 3945 INFO oslo.messaging._drivers.impl_qpid [-] Connected to AMQP server on mgmtserver:5672

2015-02-05 09:31:46.741 3945 WARNING nova.compute.manager [-] Bandwidth usage not supported by hypervisor.

2015-02-05 09:32:47.309 3945 WARNING nova.compute.manager [-] Found 1 in the database and 0 on the hypervisor.

2015-02-05 09:42:48.154 3945 WARNING nova.compute.manager [-] Found 1 in the database and 0 on the hypervisor.

Cheers

Chris