VMware vSphere Interview Questions
How will you define VMware HA?
VMware High Availability (HA) provides easy to use, cost effective high availability for applications running in virtual machines. In the event of server failure, affected virtual machines are automatically restarted on other production servers with spare capacity.
We have lot of features like VMotion, DRS, SMP etc, but why we need HA?
We need this because we need our services running without interruption. Assume like, for some reason if any one of the ESX server in the cluster goes down suddenly, what happens to the virtual machines which are running on that particular server? Are they continue to run or go down. Yes, they also goes down. But with the help of VMware HA, these vm’s can be restarted immediately on the other ESX servers in the same cluster. But here you will get a down time of 5 –10 mins. Because server crash is an unexpected thing.
What architecture changes were seen between ESXi 4.1 and 5.0?
vSphere 5.0 comes a new HA architecture. HA has been rewritten from the ground up to shed some of those constraints that were enforced by AAM. HA as part of 5.0, also referred to as FDM (fault domain manager), introduces less complexity and higher resiliency. From a UI perspective not a lot has changed, but there is a lot under the covers that has changed though, no more primary/secondary node concept as stated but a master/slave concept with an automated election process.
Is HA dependent on Vmware vCenter Server?
Yes. But only during the initial installation and configuration.
What is Hardware virtualization & Advantages of hardware Virtualization?
Transforming Hardware resources in to software layer is called Hardware virtualization, using hardware virtualization we can run multiple operating system’s concurrently on a piece of since hardware
So we can reduce Hardware Resources Save Power, cooling, Space.
Provide high available to Virtual Machines Easy to manage.
What is Virtualization?
Virtualization is creation of virtual is rather than actual version of something Such as
Hardware virtualization VMWARE VSPHERE / CITRIX XEN SERVER/ MICROSOFT HYPER V
Desktop Virtualization VMWARE VDI / CITRIX XEN DESKTOP
Application Virtualization CITRIX XEN APP / VMWARE THINK APP
What is VM Monitoring status?
HA will usually monitors ESX hosts and reboot the virtual machine in the failed hosts in the other host in the cluster in case of host isolation but i need the HA to monitors for Virtual machine failures also. here the feature called VM monitoring status as part of HA settings.VM monitoring restarts the virtual machine if the vmware tools heartbeat didn’t received with the specified time using Monitoring sensitivity.
What is VMware vSphere API and vSphere SDK?
VMware vSphere API is a set of interfaces for managing vSphere. You can use the API to do almost all the things the vSphere Client can do. The API is defined as SOAP Web Services with WSDL.
The vSphere SDK is a set of libraries that support vSphere API, as well as tools and samples that assist your development efforts. The vSphere SDK is also known as VI SDK, vCenter SDK, ESX SDK, etc.
In most discussions, the vSphere API and vSphere SDK are used interchangeably.
How does vSphere API relate to VI API?
They are essentially the same. VI was renamed as vSphere in its version 4. Accordingly, the API name got changed.
What releases of vSphere does vSphere API support?
All releases including VI 3.0, VI 3.5, vSphere 4.0, vSphere 4.1, vSphere 5.0, vSphere 5.1, vSphere 5.5, 6.0 as of 2015. Each release of vSphere has a corresponding vSphere APIs.
Can vSphere API work with VMware Server?
Yes with some versions. All are experimental though.
How does vSphere API relate to vCloud API?
They are designed for different audience in mind. You can think of vSphere API as the under-the-hook API vs. vCloud API as the drive seat API. Functionality wise, vCloud API is, almost, a subset of vSphere API. Format wise, vSphere API is SOAP based while vCloud API is REST based.
What are the products included in VMware vSphere 5.5 Bundle ?
-VMware vCenter Server
-VMware vSphere Client and Web Client
-vSphere Update Manager
-VMware vCenter Orchestrator
What is the role of VMware vCenter server?
vCenter provides a centralized management platform and framework for all ESXi hosts and their respective VMs. vCenter server allows IT administrators to deploy, manage, monitor, automate, and secure a virtual infrastructure in a centralized fashion. To help provide scalability , vCenter Server leverages a back-end database (Microsoft SQL Server and Oracle are both supported, among others) that stores all the data about the hosts and VMs.
What is the use of VMware vSphere Client and vSphere Web Client ?
vCenter Server provides a centralized management framework to VMware ESXi hosts.To access vCenter server, you need vSphere client or vSphere Web client service enabled.
What are the features included in VMware vSphere 5.5 ?
-vSphere High Availabitliy (HA)
-vSphere Fault Tolerance
-vSphere Storage vMotion
-vSphere Distributed Resource Scheduler (DRS)
-virtual SAN (VSAN)
-Flash Read Cache
-Storage I/O Control
-Network I/O Control
Will vSphere HA help on VM failures too ?
In an order to detect the VM failures, you need to enable VM Failure Monitoring. So that it detects the Disk I/O and sends the internal heartbeat to check the VM all the time. If the VM is stopped functioning, VM will be restarted automatically by vSphere HA.
What is the use of vMotion ?
Using vMotion feature,we can move the running VM’s from one ESXi host to another ESXi host without any downtime. vMotion copies the VM’s in-memory contents to the destination server and freeze the operation on current ESXi host and resumes the VM’s on remote ESXI node.
Why vMotion feature is not used/can’t use in vSphere HA ?
vMotion is used for planned migrations and possible only where the source and destination ESXI hosts are running properly.vSPhere HA is used to reduce the downtime due to failures of physical ESXi hosts.So When the failure accours on ESXi nodes, there is no time to perform vMotion and can’t be used.
How the vSphere Fault tolerance(FT) works ?
Using vLockstep technology , vSphere FT maintains the mirrored secondary VM on different ESXi physical host that is kept in lockstep with the primary.So when the primary ESXi node goes down due to hardware issue, secondary VM will immediately step-in and provide the service. At this point, this VM will become primary and secondary aka mirrored VM will be created on possible ESXI host to prevent the further ESXi failure.
What is vSphere DRS(Distributed Resource Scheduler) ? How it works ?
vSphere DRS is an intelligent frame works which always monitors the cluster nodes health check and performs the vMotion automatically whenever required. For an example ,if one of the ESXI cluster host memory has been utilized more than 90% and due to that lot of paging happening on that server. vSphere DRS detects such things in quick time and moves few VM’s to another ESXi cluster to least-balance the cluster nodes without any downtime by leveraging vMotion functionality. It applies for high contention for CPU utilization too. So vSphere DRS helps to balance the CPU & Memory utilization across the ESXi cluster nodes.
What is vSphere storage DRS ? How it works ?
vSphere Storage DRS like vSphere DRS but it applies to storage.It helps to balance storage utilization and performance between data-stores on same ESXi clusters.
What is VSAN ? How it works ?
VSAN forms the storage pools across the multiple nodes using internal disks and allows you to create a datastores that spans multiple ESXI hosts. VSAN also protect the data using VM storage profiles and you can configure it according to your requirement. You need SSD’s(Solid State Drive) to configure VSAN. Click here to learn more about VSAN.
What type of Hyper-visor VMware ESXi is ?
VMware ESXi is Bare-metal hypervisor. You can directly install on server hardware.