OpenStack OpenStack Compute (Nova) 2 — Questions and Answers
Question 1: What is a Nova 'availability zone' used for?
- Grouping services by API version compatibility
- Logically partitioning compute resources to allow tenants to select specific infrastructure zones (Correct answer)
- Setting timezone configurations for VM instances
- Defining network availability for specific compute nodes
Correct answer: Logically partitioning compute resources to allow tenants to select specific infrastructure zones
Nova availability zones allow users to specify which logical partition of compute resources to deploy instances into.
Question 2: What does the Nova 'nova-compute' service run on?
- The OpenStack controller node only
- Each individual compute (hypervisor) node (Correct answer)
- The storage node alongside Cinder services
- The network node running Neutron agents
Correct answer: Each individual compute (hypervisor) node
nova-compute runs on every compute/hypervisor node and manages the local hypervisor to create and manage VMs.
Question 3: What is 'instance shelving' in OpenStack Nova?
- Permanently archiving a VM's disk image to Swift for long-term storage
- Stopping a VM and freeing its compute resources while preserving its configuration for later restoration (Correct answer)
- Creating a snapshot of a running instance before patching
- Moving a VM to a spare compute host during maintenance
Correct answer: Stopping a VM and freeing its compute resources while preserving its configuration for later restoration
Shelving a Nova instance stops it, snapshots its disk to Glance, and frees the compute resources while preserving the instance record.
Question 4: What is a Nova 'host aggregate' used for?
- Aggregating CPU capacity statistics across all compute nodes
- Grouping compute nodes with specific hardware characteristics for targeted scheduling (Correct answer)
- Combining multiple physical servers into a single virtual compute node
- Aggregating network bandwidth across bonded NICs on compute hosts
Correct answer: Grouping compute nodes with specific hardware characteristics for targeted scheduling
Host aggregates group compute nodes by hardware properties (e.g., GPU, SSD) and use metadata to guide Nova scheduler placement.
Question 5: What happens to an instance's ephemeral disk when a Nova instance is terminated?
- It is automatically converted to a Cinder volume
- It is permanently deleted along with the instance (Correct answer)
- It is stored as a Glance image for future use
- It is moved to a quarantine zone for 30 days
Correct answer: It is permanently deleted along with the instance
When a Nova instance is terminated, its ephemeral disk is permanently deleted as ephemeral storage is tied to instance lifecycle.
Question 6: What is the role of 'cloud-init' in Nova instance provisioning?
- Initializing the Nova compute service at system startup
- A tool that configures VM instances at first boot using user-data and metadata (Correct answer)
- Starting the cloud infrastructure management services
- Pre-configuring network interfaces before Nova deploys an instance
Correct answer: A tool that configures VM instances at first boot using user-data and metadata
cloud-init is a standard tool that runs at instance first boot to configure users, SSH keys, packages, and run scripts from user-data.
OpenStack OpenStack Compute (Nova) 2
What is a Nova 'availability zone' used for?