Availability zone - An Amazon EC2 concept of an isolated area that is used for fault tolerance. Do not confuse with an OpenStack Compute zone or cell. Availability Zones are an end-user visible logical abstraction for partitioning a cloud without knowing the physical infrastructure.
CIDR - representation (<IP>/<prefix length>) of the network’s IP subnet.
CEPH - Massively scalable distributed storage system that consists of an object store, block store, and POSIX-compatible distributed file system. Compatible with OpenStack.
Port - A virtual network port within Networking; VIFs / vNICs are connected to a port.
Ingress - The process of filtering incoming network traffic. Supported by Compute.
Ephemeral volume - Volume that does not save the changes made to it and reverts to its original state when the current user relinquishes control.
External Network - A network segment typically used for instance Internet access.
Floating IPs - An IP address that a project can associate with a VM so that the instance has the same public IP address each time that it boots. You create a pool of floating IP addresses and assign them to instances as they are launched to maintain a consistent IP address for maintaining DNS assignment.
Flavor - is an available hardware configuration for a VM instance. It defines the size of a virtual server that can be launched. Flavors define the compute, memory, and storage capacity of nova computing instances.
GateWay IP - An IP address, typically assigned to a router, that passes network traffic between different networks.
Instances - A running VM, or a VM in a known state such as suspended, that can be used like a hardware server.
Images - A collection of files for a specific operating system (OS) that you use to create or rebuild a server. OpenStack provides pre-built images. You can also create custom images, or snapshots, from servers that you have launched. Custom images can be used for data backups or as images for additional servers.
Key pairs - are SSH credentials that are injected into an instance when it is launched.A key pair belongs to an individual user, not to a project. To share a key pair across multiple users, each user needs to import that key pair.
Live migration - The ability within Compute to move running virtual machine instances from one host to another with only a small service interruption during switchover.
Network - A virtual network that provides connectivity between entities. For example, a collection of virtual ports that share network connectivity. In Networking terminology, a network is always a layer-2 network.
Openstack - is a cloud operating system that controls large pools of compute, storage, and networking resources throughout a data center, all managed through a dashboard that gives administrators control while empowering their users to provision resources through a web interface. OpenStack is an open source project licensed under the Apache License 2.0.
Persistent volume - Changes to these types of disk volumes are saved.
Public image - An Image service VM image that is available to all projects.
Public Key Authentication - Authentication method that uses keys rather than passwords Backups.
QCOW2 (QEMU copy-on-write version 2) - One of the VM image disk formats supported by Image service.The QCOW image format is one of the disk image formats supported by the QEMU processor emulator. It is a representation of a fixed size block device in a file.
RAW - One of the VM image disk formats supported by Image service; an unstructured disk image. The raw image format is the simplest one, and is natively supported by both KVM and Xen hypervisors. You can think of a raw image as being the bit-equivalent of a block device file, created as if somebody had copied, say, /dev/sda to a file using the dd command
Routers - A physical or virtual network device that passes network traffic between
Subnet - Logical subdivision of an IP network.
Security group - A set of network traffic filtering rules that are applied to a Compute instance.
Volumes - Disk-based data storage generally represented as an iSCSI target with a file system that supports extended attributes; can be persistent or ephemeral.
XFS - High-performance 64-bit file system created by Silicon Graphics. Excels in parallel I/O operations and data consistency.
X509 Certificate - is a standard format for public key certificates, digital documents that securely associate cryptographic key pairs with identities such as websites, individuals, or organizations.