OpenStack Compute (Nova) Flashcards

What is a Nova 'availability zone' used for?

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.

What does the Nova 'nova-compute' service run on?

Answer: Each individual compute (hypervisor) node

nova-compute runs on every compute/hypervisor node and manages the local hypervisor to create and manage VMs.

What is 'instance shelving' in OpenStack Nova?

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.

What is a Nova 'host aggregate' used for?

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.

What happens to an instance's ephemeral disk when a Nova instance is terminated?

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.

What is the role of 'cloud-init' in Nova instance provisioning?

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.