OpenStack Top Interview Questions And Answers: 2020 Edition

1. Explain what is OpenStack?

OpenStack is a set of software tools for managing and building cloud computing platforms and also used for handling a large group of virtual machines with the help of the graphical user interface. The working of OpenStack is similar to Linux and It is a free and open-source software cloud computing platform.

2. What are the advantages of using OpenStack?

The following are the advantages of using Openstack:

• OpenStack provides a strong foundation in delivering the self-storage
• It is very easy to handle low-cost storage by using OpenStack
• Using OpenStack, licensing fees can be managed because virtual machines are used in OpenStack.

3. How many types of storages are provided by the Openstack?

Openstack provides two types of storages:

• Ephemeral storage
• Persistent storage

4. Name the three important modular architecture of OpenStack?

The following are the three modular architecture components for OpenStack

• OpenStack Compute: This is used for managing large networks on virtual machines. 
• OpenStack Object Storage: It acts as a storage system and provides support for object storage devices and block storage devices.
• Image Service:  It is used as a delivery service and provides delivery for discovering and registering images of virtual machines. 

5. What is the command used for managing floating IP addresses in Openstack?

nova floating-IP-* 

6. Give an overview of OpenStack Services?

OpenStack offers services like

• Keystone: It is used for providing an identity list and is used for authentication of users. 
• Glance: It provides the image information of the hard disks and also Manages images in different formats
• Cinder: Provides persistent block storage
• Neutron: It is used for building connectivity between components as it enables users to create and attach interfaces to networks.
• Nova: Provides instances on user’s demand
• Swift: Storage platform integrated directly into applications
• Ceilometer: Openstack for billing
• Heat: Allows automated infrastructure deployment

7. What does “User”, “role” and “tenant” indicate in OpenStack?

• User: Users are members of multiple projects in OpenStack
• Tenant: Tenant is referred to as a group of users in OpenStack. It is also known as a project or accounts. 
• Role: It is defined as the position which is used for authorizing or mapping the user.

8. What is a hypervisor? 

The hypervisor is a piece of computer software that provides virtual machine access to the underlying hardware. The hypervisor creates, manages and monitors virtual machines and the system on which one or more virtual machines are defined is referred to as the host machine.

9. What are the types of hypervisor does OpenStack supports? 

• KVM
• VMware
• Containers
• Xen and HyperV

10. What are the two types of storage does OpenStack Compute provides?

OpenStack provides two types of block storage,

• Ephemeral Storage: The size is defined based on the instance as Ephemeral storage is associated with a single unique instance. In the same way, the instance associated with is terminated, then data on ES ceases to exist. 
• Persistent Storage: This storage is also called as Volume Storage. Unlike ES, this storage is not dependent on any instance and is persistent. 

11. What are the three types of persistent storage?

The Three types of Persistent Storage are:

• Object storage
• Block storage
• File-based storage

12. Explain the basic functions of Identity Service in OpenStack?

The basic functions of Identity Service are

• User Management:  It tracks the users along with their permissions
• Service Catalog: It provides a catalog of available services along with their API endpoints

13. What are the main components of identity user management?

• Users: It represents a person, service or system who uses the services of OpenStack Cloud. 
• Tenants: Depending on the service operator a tenant is used for authorizing and authenticating a customer, account, organization or project. 
• Roles:  A role includes a certain set of rights and privileges and it determines the operations in which a user can perform in a given tenant.  

14. Name the networking options used in OpenStack?

The following are the networking options used in OpenStack 

• Flat Network Manager
• Flat DHCP Network Manager
• VLAN Network Manager

15. What is the meaning of the term “Cinder” in OpenStack service?

OpenStack provides a service called cinder for handling persistent storage for virtual machines. There are multiple backends for cinder and the default backend which is utilized is LVM, also called Cinder-Volumes.

16. List out the storage locations for VM images in OpenStack?

• OpenStack Object Storage
• Filesystem
• S3
• HTTP
• RBD or Rados Block Device
• GridFS

17. Explain what is Cells in OpenStack?

Cells are the groups that are separated from the hosts of the OpenStack compute cloud. Cells later configured as trees. 

18. What is the hardware used for networking in OpenStack?

The following are the hardware used for networking in OpenStack

• Networks
• Routers
• Subnets
• Ports
• Vendor Plugins

19. How can you transfer volume from one owner to another in OpenStack?

We can transfer a volume from one owner to another by using the command

cinder transfer*

20. What is the bare-metal node? 

A bare-metal node is used for a single-tenant cloud and gives access to bare metal drivers, which is used for handling physical hardware resources on the same network. 

21. What does bare-metal comprise of?

The bare metal node comprises of two separate components

• Bare metal node Orchestrator: It is management software, which is used as a dispatcher to all nodes in the cluster.
• Bare metal node Operating System: It is a base software, which runs on each separate node in the cluster.

22. What is the command used to remove the network interface from the bare-metal node?

Command used to remove network interface from the bare-metal node is bare-metal – interface remove.

23. What is the function of the Cinder Scheduler?

Cinder Scheduler is also known as routing volume which is used to create requests for appropriate volume service. 

24. What is meant Token in OpenStack?

The token is an alpha-numeric string that is similar to passed-based validation which is used for the authentication of keystone. With the generated token users can access a certain set of services depending upon the access level of the user. The token comes with a limited period of time. Once the given time period exceeds, it has to be renewed again. 

25. Explain about OpenStack Python SDK?

SDK(Software Development Kit) is used for writing python scripts and provides a platform for OpenStack where all the services can be managed in one place. The languages in SDK bind access to the OpenStack clouds, and complete API reference with easy interaction with REST API

26. What are the commands used for pausing and unpausing an instance?

Command used to pause an Instance:

$ nova pause INSTANCE_NAME

Command used to unpause an instance:

$ nova unpause INSTANCE_NAME

27. What is the command used for listing IP address information?

$ nova floating-IP-pool-list

28. What is meant by the term “flavor” in OpenStack?

The term flavor in OpenStack refers to an available hardware configuration for a server, which defines the size of a virtual server that is to be launched.

For More Information, visit our website: https://www.iqonlinetraining.com