Comment 3 for bug 1255624

> 2013-11-27 17:29:40.345 23415 TRACE nova.openstack.common.rpc.amqp libvirtError: Unable to read from monitor: Connection reset by peer

This error message from libvirt indicates that the QEMU monitor has closed the connection. This is usually a result of QEMU crashing, or being killed. I've never seen this happen in response to a virDomainSuspend API call.

To further diagnose this you need to examine more logs, in particular /var/log/libvirt/qemu/$GUESTNAME.log - if we're lucky (we're usually not) then this may indicate why QEMU crashed. Also check /var/log/messages for stupid things like the OOM killer going mental & slaughtering QEMU.