OpenStack OpenStack Compute (Nova) 1 — Questions and Answers
Question 1: Which OpenStack service manages the lifecycle of virtual machine instances?
- Cinder
- Nova (Correct answer)
- Neutron
- Ironic
Correct answer: Nova
Nova is the OpenStack Compute service responsible for creating, scheduling, and managing virtual machine instances.
Question 2: What is a Nova 'flavor' in OpenStack?
- A pre-installed software configuration for a VM image
- A hardware profile defining vCPUs, RAM, and disk size for VM instances (Correct answer)
- A set of cloud-init scripts run at instance boot
- A network configuration template applied to new VMs
Correct answer: A hardware profile defining vCPUs, RAM, and disk size for VM instances
A Nova flavor defines the virtual hardware profile (vCPUs, RAM, disk) of a VM instance, analogous to an EC2 instance type.
Question 3: What is Nova's scheduler responsible for?
- Scheduling periodic Cron jobs on compute nodes
- Selecting the most appropriate compute host for a new VM based on filters and weights (Correct answer)
- Managing the timeline of VM lifecycle state changes
- Distributing API requests across multiple Nova API endpoints
Correct answer: Selecting the most appropriate compute host for a new VM based on filters and weights
The Nova scheduler selects the best compute host for a new instance using configurable filters and weighers.
Question 4: What hypervisor does Nova use by default in most production deployments?
- VMware ESXi
- Microsoft Hyper-V
- KVM (Kernel-based Virtual Machine) (Correct answer)
- Xen
Correct answer: KVM (Kernel-based Virtual Machine)
KVM is the most widely deployed hypervisor for OpenStack Nova in production environments due to its performance and Linux integration.
Question 5: What is the purpose of Nova's 'nova-conductor' service?
- Conducting live performance monitoring of VM instances
- Providing a database access proxy to prevent compute nodes from directly accessing the Nova database (Correct answer)
- Managing the lifecycle of Nova API workers
- Coordinating storage attachment between Nova and Cinder
Correct answer: Providing a database access proxy to prevent compute nodes from directly accessing the Nova database
nova-conductor acts as a database proxy layer, preventing compute nodes from having direct database access for improved security.
Question 6: What is 'live migration' in Nova?
- Moving a VM's persistent Cinder volume to a different storage backend
- Migrating a running VM instance from one compute host to another without downtime (Correct answer)
- Upgrading a VM's OS while it continues running
- Changing a VM's flavor while the instance is active
Correct answer: Migrating a running VM instance from one compute host to another without downtime
Live migration in Nova moves a running VM from one compute host to another with minimal or zero downtime.
OpenStack OpenStack Compute (Nova) 1
Which OpenStack service manages the lifecycle of virtual machine instances?