OpenStack Image Service (Glance) & Dashboard (Horizon) Flashcards

Which OpenStack service stores and retrieves virtual machine disk images?

Answer: Glance

Glance is the OpenStack Image Service that stores, discovers, and retrieves VM disk images used to boot instances.

What is OpenStack Horizon?

Answer: A web-based dashboard providing a graphical interface to OpenStack services

Horizon is OpenStack's web-based dashboard that provides a GUI for users and administrators to interact with OpenStack services.

Which disk image format is most commonly used for QEMU/KVM instances in OpenStack Glance?

Answer: QCOW2

QCOW2 (QEMU Copy-On-Write version 2) is the standard disk image format for KVM-based OpenStack deployments.

What is the 'visibility' property of a Glance image?

Answer: Controls who can see and use the image (public, private, shared, community)

Glance image visibility controls access: 'public' images are available to all tenants, 'private' only to the owner.

What is 'cloud-config' user data commonly used for when launching OpenStack instances?

Answer: Providing declarative configuration instructions to cloud-init for automated instance setup

Cloud-config is a YAML format processed by cloud-init to perform automated instance configuration tasks at first boot.

Where does Glance store image data by default in a basic OpenStack deployment?

Answer: In the local filesystem of the Glance service node

By default, Glance stores image files in the local filesystem of the host running the Glance service, typically at /var/lib/glance/images/.