COA Troubleshooting & Problem Resolution 2

Question 1

An instance is stuck in 'ERROR' state after a failed live migration. Which command retrieves the error details from the Nova compute log?

Accepted Answer

openstack server show <instance-id>

Answer

The 'openstack server show' command displays fault messages and the last error that caused an instance to enter ERROR state.

Question 2

After updating the Neutron ML2 plugin configuration, the neutron-server fails to start. What is the first log file you should inspect?

Accepted Answer

/var/log/neutron/server.log

Answer

The neutron-server.log captures startup errors including plugin misconfiguration, making it the primary source for server-start failures.

Question 3

A tenant reports that their floating IP is assigned but they cannot reach the instance from the internet. Which Neutron resource should you verify first?

Accepted Answer

Router external gateway association

Answer

A floating IP requires a router with an external gateway set; without it, NAT cannot route traffic between the external network and the tenant network.

Question 4

You run 'openstack volume list' and see a volume stuck in 'attaching' state for over 30 minutes. What is the recommended corrective action?

Accepted Answer

Run openstack volume set --state available <vol-id>

Answer

Forcing the Cinder volume state back to 'available' with 'openstack volume set --state' unblocks stuck attach operations without data loss.

Question 5

Which command verifies that all Nova compute services are up and reporting correctly across the deployment?

Accepted Answer

openstack compute service list

Answer

'openstack compute service list' shows the state and status of every Nova service node, including whether each is 'up' or 'down'.

(COA) Certified OpenStack Administrator Exam Practice Test

(COA) Certified OpenStack Administrator Exam Practice Test

COA Troubleshooting & Problem Resolution 2