What is OpenStack?
Most multinational organizations define OpenStack as the future of Cloud Computing. The Internet and large volumes of data together have instigated the purpose of cloud computing, and OpenStack is one such platform to create and handle massive groups of virtual machines through a Graphical User Interface. It is a set of efficient software tools to manage private and public cloud computing platforms.
Openstack is free, open-source software and works similar to Linux.
Explain the benefits of using OpenStack Cloud.
Openstack is useful in developing any software-as-a-service (SAAS) applications, for new developments or to improve existing solutions.
- Can serve as a strong foundation to deliver self-service storage to IT users.
- Can deliver on-demand objective or block storage with higher scalability and easy-to-handle storage at lower costs.
- Most enterprises can save bigger on licensing fees by switching virtual machines running on VMware to OpenStack.
Mention the three main components of OpenStack.
The architecture of the OpenStack developmental software program is made of three main components –
1. The image service – The virtual disk images are registered and also discovered by this service provided by OpenStack.
2. Computing – The management of a large network over the Internet is also done in a good way by OpenStack.
3. Storing Object – Two types of storage, block and object are both supported by the system of OpenStack.
How many types of block storage ads provided by OpenStack?
Mainly two types of block storage are provided by OpenStack :
- Volume Storage – This type of storage refers to the independent ones. These are persistent in nature.
- Ephemeral Storage – This type of storage is an example of a single storage instance. After the termination of a virtual machine, or generally disappears.
Where are the VM images stored in OpenStack?
The list of locations of VM images are as follows –
- File system
- HTTP
- Object storage by OpenStack
- GridFS
- Rados Block Device
- S3
Name the key components of Openstack
Following are the key components of OpenStack
- Nova – It handles the Virtual machines at compute level and performs other computing task at compute or hypervisor level.
- Neutron – It provides the networking functionality to VMs, Compute and Controller Nodes.
- Keystone – It provides the identity service for all cloud users and openstack services. In other words, we can say Keystone a method to provide access to cloud users and services.
- Horizon – It provides a GUI (Graphical User Interface), using the GUI Admin can all day to day operations task at ease.
- Cinder – It provides the block storage functionality, generally in OpenStack Cinder is integrated with Chef and ScaleIO to service block storage to Compute & Controller nodes.
- Swift – It provides the object storage functionality. Generally, Glance images are on object storage. External storage like ScaleIO can work as Object storage too and can easily be integrated with Glance Service.
- Glance – It provides Cloud image services, using glance admin used to upload and download cloud images.
- Heat – It provides an orchestration service or functionality. Using Heat admin can easily VMs as stack and based on requirements VMs in the stack can be scale-in and Scale-out
- Ceilometer – It provides the telemetry and billing services.
What are the modular architectural components of OpenStack?
Following is a list of OpenStack modular architectural components:
- Dashboard
- Compute
- Networking
- Object Storage
- Block Storage
- Identity service
- Image Service
- Telemetry
- Orchestration
- Database Service etc.
What is “role” and “tenant” in OpenStack?
role: It specifies the authorization level of the user.
Tenant: It specifies a group of users.
What are the storage types allowed by OpenStack compute?
OpenStack supports two types of storage:
1. Persistent Storage or volume storage
2. Ephemeral Storage
Persistent Storage / Volume Storage: It is persistent and independent of any particular instance. This storage is created by users. There are three types of persistent storage:
- Object storage: It is used to access binary objects through the REST API.
- Block storage: It offers access-to-block storage devices by affixing volumes their current VM instances.
- Shared File System storage: It provides a set of services to manage multiple files together for storage and exchange with multiple users at one time.
Ephemeral Storage: The ephemeral storage specifies a single instance. It is temporary and short-lived storage that is disappeared once the VM is terminated.
What are the different networking options used in OpenStack?
The networking options used in Open Stack are:
- Flat DHCP Network Manager: It is used to fetch IP addresses from the subnet for VM instances but IP addresses to VM are assigned via DHCP (Dynamic Host Configuration Protocol).
- Flat Network Manager: It is used to fetch IP addresses from the subnet for VM instances, and then injected into the image on launch.
- VLAN Network Manager: : VLAN provides more secure and separate network to VMs. It has a physical switch to offer separate virtual network and separate IP range and bridge for each tenant. It is more preferable choice.
What is Token in OpenStack?
Token is a type of authentication like password-based validation. It is generated when the user inserts the credential and authenticate as a keystone user then Tokens can be used to access OpenStack services without any revalidation.
What are the commands used to generate key pairs in OpenStack?
Commands used to generate key pairs in OpenStack:
- ssh-keygen
- cd.ssh
- nova keypair-add -pub_key id_rsa.pub mykey
Which hardware is required for networking in OpenStack?
In OpenStack, networking can be done with following hardware:
- Networks
- Routers
- Subnets
- Ports
- Vendor Plugins
What is the role of Tunnel Bridge (br-tun) on the compute node?
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
What is CPU pinning?
CPU pinning refers to reserving the physical cores for specific virtual machine. It is also known as CPU isolation or processor affinity. The configuration is in two parts:
- it ensures that virtual machine can only run on dedicated cores
- it also ensures that common host processes don’t run on those cores
In other words, we can say pinning is one to one mapping of a physical core to a guest vCPU
What is the meaning of ‘Flavor’ in OpenStack?
OpenStack provides various hardware templates which are found virtually and they are known as Flavor. Generally, the size of the memory of any hard disk and RAM is defined by it. In fact, various components like Name, ID, Disk, Memory are all illustrated by it. The flavor can be modified in the OpenStack.
How do Account Reaper works?
Data in the deleted accounts which are not used by the users are removed with the help of Account Reaper.
Define bare-metal node. What are its components?
The hardware resources can be controlled by users with the help of bare metal nodes which gives the users the right to control the bare metal driver. Its components are –
- Bare metal node operating system – The is considered to be the software base for various nodes present in the cluster.
- Bare metal node orchestrator – All the nodes when dispatched in the cluster is managed by this software.
What types of commands are used for the generation of Key pairs?
The following are the different commands which can be used –
- cd.ssh
- ssh-keygen
- Nova keypair – add – pub_key id_rsa.pub mykey
What is Hypervisor?
VMM which is the abbreviation of virtual machine monitor is basically defined by the Hypervisor. It is also used to define various components like firmware, hardware, and software. All these are part of the virtual machine. A hypervisor is mainly consisted or included by the host machine or various other virtually available machines. Multiple Hypervisor is also available in the OpenStack developmental software program and can choose accordingly catering to specific uses.
What are the different types of Hypervisor available in the OpenStack developmental software program?
The following are the lists of Hypervisors available in the OpenStack developmental software program are –
- KVM – Kernel Virtual Machine
- QEMU – Quick EMUlator and these are used for the purpose of development
- LXC – Linux VMs are present in this Linux Containers
- UML – For the development of the system, User Mode Linux can be used
- Hyper-V – Virtualization of the server
- VMware vSphere – Includes VMware Linux
What are the different networking options that are available in OpenStack?
The following are the different types of networking options –
- Capacity Filter – This type of filtering is mainly based on the capacity consumption of the volume host.
- Availability Zone Filter – Filter did according to the zones available.
- Different Backend Filter – Done by the volume scheduled to the various back end.
- Retry Filter – Filtering existing hosts.
- JSON Filter
Apart from the above, some other networks are:
- Flat network manager
- VLAN network manager
- Flat DHCP network manager
What are the various functions of the command ‘nova’?
The functions of nova are as follows –
- Compute resources are well managed
- Authorization and networking
- API based on the REST
- Communication which is asynchronous
- Supports Xen several and is hence considered to be Hypervisor agnostic
- Helps in the management of instances
Define Sanitization Process.
The sanitization process refers to the process of the removal of certain information that is present in the media. This type is information is basically useless as these can’t be reconstructed or retrieved. This process mainly includes various techniques like purging, clearing, erasing cryptographically, and also destruction. Such a process prevents the information to get out to any individuals who are unauthorized during the releases of such information in the media.
Explain networking techniques used in OpenStack?
Flat DHCP Network Manager: In this technique, IP addresses are fetched from the subnet for virtual machine instances but IP addresses to VM are allocated by using DHCP (Dynamic Host Configuration Protocol).
Flat Network Manager: In this technique, IP addresses are fetched from the subnet for VM instances, and then inserted into the image while launching.
VLAN Network Manager: VLAN is better and more preferred than the above two techniques as it offers a separate and secure network to virtual machines. There is a physical switch to provide a separate virtual network and separate IP range and bridge to every tenant.
What are the endpoints of OpenStack services?
Endpoints of Openstack services are classified as:
- Public Endpoint
- Internal Endpoint
- Admin Endpoint
