Error in devstack script. nova-api did not start?

Question

I have installed openstack on Ubuntu 12.04 single node using devstack. Now, it was running smoothly till yesterday. When i ran ./stack.sh today, it showed an error

./stack.sh:672 nova-api did not start

I have python-paste and python-pastedeploy installed. How to fix this error?

Answer 1

General rule of thumb for devstack.

Always unstack.sh before re-running stack.sh or pulling from repositories and re-running stack.sh

Answer 2

check out for errors in nova api screen run this command to open screens

screen -x stack

open n-api screen ususally ( Ctrl + A + 5 ). Check for errors and then restart Nova API with this command.

cd /opt/stack/nova && /usr/local/bin/nova-api & echo $! >/opt/stack/status/stack/n-api.pid; fg || echo "n-api failed to start" | tee "/opt/stack/status/stack/n-api.failure"