OpenStack Interview Questions

Question1 – difference between cloud and virtualization
Virtualization is technology that separates functions from hardware, while clouds rely on that split. … Assuming intranet access, internet access, or both is already established, virtualization is what creates clouds. Software called a hypervisor sits on top of physical hardware and abstracts the machine’s resources.

Question2- different cloud vendors in market ?

Answer –

Below mentioned are the top Cloud Computing Companies

  • Kamatera
  • phoenixNAP
  • Amazon Web Services
  • Microsoft Azure
  • Google Cloud Platform
  • Adobe
  • VMware
  • IBM Cloud
  • Rackspace
  • Red Hat
  • Salesforce
  • Oracle Cloud
  • SAP
  • Verizon Cloud
  • Navisite
  • Dropbox
  • Egnyte

Question3- Define Openstack?
OpenStack is a set of software tools for building and managing cloud computing platforms for public and private clouds.

Question4-Give An Overview Of Openstack Services?
Answer :
OpenStack offers services like :
Glance: Manages images in different formats
Ceilometer: Openstack for billing
Cinder: Provides persistent block storage
Neutron: Enables users to create and attach interfaces to networks
Nova: Provides instances on user’s demand
Swift: Storage platform integrated directly into applications
Heat: Allows automated infrastructure deployment
Keystone: Provides authorization and authentication for users

Question5. What Are The Basic Functions Of Identity Service In Openstack?
Answer :
The basic functions of Identity Service is:
Service Catalog: It provides a catalog of available services with their API endpoints
User Management: It tracks the users and their permissions

Question6- Typeys of deplyment explain any one

Question7 – Triple O installation

Question8- What You Mean By Tenant And Role Regarding Openstack ?
In OpenStack,  the authorization level of the user is called role and the group of users is called tenant.

Question9- What are services generally run on a controller node?
• Identity Service ( KeyStone)
• Image Service ( Glance)
• Nova Services like Nova API, Nova Scheduler & Nova DB
• Block & Object Service
• Ceilometer Service
• MariaDB / MySQL and RabbitMQ Service
• Management services of Networking (Neutron) and Networking agents
• Orchestration Service (Heat)

Question 10. Explain What Hypervisor Is And What Type Of Hypervisor Does Openstack Supports?
Answer :
In virtualization technology, hypervisor is a software program that manages multiple operating systems (or multiple instances of the same operating system) on a single computer system.
The types of hypervisor that OpenStack supports are :
Xen and HyperV

11- What are the services generally run on a Compute Node?
• Nova-Compute
• Networking Services like OVS
12- What is the default location of VMs on the Compute Nodes? – default –> /var/lib/nova/instances
13- What is default location of glance images? – default –> /var/lib/glance/images
14- How to get list of available Floating IPs from command line?
~]# openstack ip floating list | grep None | head -10
Question 15. What Is The Meaning Of Term “cinder” In Openstack Service?
Answer :
Cinder is used for handling persistent storage in OpenStack.The one that is utilized by default is LVM, called Cinder-Volumes.
Question 16. What Is The Command Used For Unpause And Pause An Instance?
Answer :
To unpause an instance – $ nova unpause INSTANCE_NAME
To pause an instance – $ nova pause INSTANCE_NAME
Question 17. Explain What Is The Function Of Cinder Scheduler?
Answer :
Cinder Scheduler or routing volume create requests to the appropriate volume service
Question 18. Explain What Is Token In Openstack?
Answer :
Token is an alpha-numeric string which allows access to a certain set of services depending upon the access level of the user
Question 19. What Is The Command To Manage Floating Ip Addresses In Openstack?
Answer :
nova floating-ip-*
Question 20. What Is The Meaning Of Term “flavor” In Openstack?
Answer :
A flavour is an available hardware configuration for a server, which defines the size of a virtual server that can be launched.
Question 21. What Is The Command Used To List Ip Address Information?
Answer :
$ nova floating-ip-pool-list
Question 22. What Are Functions Of “nova” ?
Answer :
Instance life cycle management
Management of compute resources
Networking and Authorization
REST-based API
Asynchronous eventually consistent communication
Hypervisor agnostic : support for Xen, XenServer/XCP, KVM, UML, VMware vSphere and Hyper-V
Question 23. What Is Rabbit Mq Server ?
Answer :
OpenStack communicates among themselves using the message queue via AMQP.
Question 24. What Are Functions And Features Of Swift ?
Answer :
Storage of large sized objects
Storage of large number of objects
Data Redundancy
Archival capabilities – Work with large datasets
Data container for virtual machines and cloud apps
Media Streaming capabilities
Secure storage of objects
Extreme scalability
Backup and archival
Question 25. What Do You Understand By Horizon ?
Answer :
Horizon the web based dashboard can be used to manage /administer OpenStack services.
Question 26. What Is Orchestration ?
Answer :
Orchestration is an orchestration engine that provides the possibility to launch multiple composite cloud applications based on templates in the form of text files that can be treated like code.
Q:27 How to view the OVS bridges configured on Controller and Compute Nodes?
~]# ovs-vsctl show
Q:28 What is the role of Integration Bridge(br-int) on the Compute Node ?
Ans: The integration bridge (br-int) performs VLAN tagging and untagging for the traffic coming from and to the instance running on the compute node.
Packets leaving the n/w interface of an instance goes through the linux bridge (qbr) using the virtual interface qvo. The interface qvb is connected to the Linux Bridge & interface qvo is connected to integration bridge (br-int). The qvo port on integration bridge has an internal VLAN tag that gets appended to packet header when a packet reaches to the integration bridge.
Q:29 What is the role of Tunnel Bridge (br-tun) on the compute node?
Ans: The tunnel bridge (br-tun) translates the VLAN tagged traffic from integration bridge to the tunnel ids using OpenFlow rules.
br-tun (tunnel bridge) allows the communication between the instances on different networks. Tunneling helps to encapsulate the traffic travelling over insecure networks, br-tun supports two overlay networks i.e GRE and VXLAN
Q:30 What is the role of external OVS bridge (br-ex)?
Ans: As the name suggests, this bridge forwards the traffic coming to and from the network to allow external access to instances. br-ex connects to the physical interface like eth2, so that floating IP traffic for tenants networks is received from the physical network and routed to the tenant network ports.
31. What is Token?
The token is a kind of verification like keyword based approval. A token gets created once the client embeds the certifications and validates as a Keystone client. The token would then be able to be utilized to get to OpenStack services with no revalidation. It is usually interesting take note of that a token is dynamic for a constrained period and must be recharged after normal interims.
To make a token, clients first need to validate their Keystone accreditations.

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