Interview Questions On VMware
Interview question on vmware which is helpful for interview.
Below are the Interview question of vmware in details:
Question 1- What is the difference between Affinity and Anti-Affinity rules and from where we create them?
Affinitty rule means both the VMs will stick to the same host always. These VMs cannot be separated either by a vMotion or Automated DRS.
Anti-Affinity rule means both the VMs will stay on separate ESXi hosts. They will never be together except in HA if the number of hosts in cluster are less.
Note-If the VM is a windows clustered VM with RDM’s than in this case what is the purpose of creating anti-afinity rule when that VM with RDM can not be vMotioned so DRS has no chance of moving it.
Question 2- What is the difference between E1000 and VMXNET3 network adapters
The E1000 virtual NIC is a software emulation of a 1 GB network card.
The VMXNET3 virtual NIC is a completely virtualized 10 GB NIC.
Question 3- What is vCenter Single Sign-On (SSO)?
Is SSO a replacement for my Active Directory or LDAP setup and management?
Difference between SSO and active directory
SSO can add multiple AD domains, OpenLDAP, and the local operating system where SSO is deployed. It also lets you create local users and groups.
SSO now allows VMware vSphere to connect to a non-AD Identity Source, OpenLDAP.
You can also assign vCenter Server privileges to users and groups from this internal datastore
SSO is an authentication service that implements the brokered authentication architectural pattern.
The SSO server provides an authentication interface called Security Token Service (STS).
Active Directory helps you organize your company’s users, computer and more.
Active Directory use for centralized domain management
Question 4- Limits on Simultaneous Migrations
Network limits apply only to migrations with vMotion. Network limits depend on the version of ESXi
Host Migration Limits and Resource Costs for vMotion, Storage vMotion
Question 5- Difference between window failover clustering and vmware HA
In the case of VMware HA there is a single instance of the virtual machine (with the application) to be protected.
MSCS solution requires two independent Windows nodes
In the case of VMware HA, you are really only monitoring the status of the physical server. Should a physical server go down the virtual machine is restarted on another node of the cluster.
Microsoft Cluster Server solution you would typically be able to be protected by physical host failures (obviously) and you also would be able to monitor the application status so that a given service can be restarted onto another MSCS node should it fail to start on the “primary” node even if the node has not failed.
Question 6- What is task of Platform Services Controller (PSC)
Platform Services Controller Interface, a fully HTML5-based interface to administer and configure many of the services that run on the PSC.
Using the Platform Services Controller Interface you can perform tasks, such as:
Adding and Editing Users and Groups for Single Sign-On
Adding Single Sign-On Identity Sources
Configuring Single Sign-On Policies (e.g Password Policies)
Adding Certificate Stores
Adding and Revoking Certificates
Question 7- what is difference between hostd, Vpxa and vpxd.
VPXD-It is Vcenter Server Service. If this service is stopped then we will not able to connect to Vcenter Server via Vsphere client.
VPXA-It is the agent of Vcenter server. also known as mini vcenter server which is installed on the each esx server which is managed by Vcenter server. What are the management action we are performing on top of the vcenter server. (Like:- Increasing/Decreasing RAM & HDD, Making any type of changes in cluster,doing vmotion. This agent collects all information from the vcenter server and pass this information to the kernal of the esx server.
HOSTD- This is the agent of ESX server, here VPXA pass the information to the HOSTD and hostd pass the information to ESX server.
Question 8- What is content library.
Content libraries are container objects for VM templates, vApp templates, and other types of files. vSphere administrators can use the templates in the library to deploy virtual machines and vApps in the vSphere inventory. Sharing templates and files across multiple vCenter Server instances in same or different locations brings out consistency, compliance, efficiency, and automation in deploying workloads at scale.
You create and manage a content library from a single vCenter Server instance, but you can share the library items to other vCenter Server instances if HTTP(S) traffic is allowed between them.
You can create two types of libraries: local or subscribed library.
You use a local library to store items in a single vCenter Server instance. You can publish the local library so that users from other vCenter Server systems can subscribe to it. When you publish a content library externally, you can configure a password for authentication.
VM templates and vApps templates are stored as OVF file formats in the content library. You can also upload other file types, such as ISO images, text files, and so on, in a content library.
You can create a subscribed library and populate its content by synchronizing to a local library. A subscribed library contains copies of the local library files or just the metadata of the library items. The local library can be located on the same vCenter Server instance as the subscribed library, or the subscribed library can reference a local library on a different vCenter Server instance
Question 9- Cross vCenter vMotion
Prior to vSphere 6.0, we were not allowed to perform the live migration between the vSphere Distributed Switches. It was only limited within the dvswitch. After vSphere 6.0, vMotion is allowed across vSwitches and even vCenter Servers.
To enable migration across vCenter Server instances, your environment must meet these requirements:
The source and destination vCenter Server instances and ESXi hosts must be running version 6.0 or later.
The cross vCenter Server and long distance vMotion features require an Enterprise Plus license.
When using the vSphere Web Client, both vCenter Server instances must be in Enhanced Linked Mode and must be in the same vCenter Single Sign-On domain so that the source vCenter Server can authenticate to the destination vCenter Server.
Both vCenter Server instances must be time-synchronized with each other for correct vCenter Single Sign-On token verification.
For migration of compute resources only, both vCenter Server instances must be connected to the shared virtual machine storage.
Question 9- What is Cross-vSwitch vMotion
With vSphere 6.0, It is possible to perform migration across Virtual switches (Standard switch or Distributed Switch), which transfers all the VDS port metadata during the migration. It is entirely transparent to the Guest VM’s and No downtime is required to perform this operation across vSwitches. Only one requirement for the migration across vSwitches is that you should have L2 VM Connectivity.
Virtual Networking Migration
|Source Type||Destination Type||Supported|
|Distributed Switch||Distributed Switch||Yes|
|Distributed Switch||Standard Switch||No|
|Standard Switch||Standard Switch||Yes|
|Standard Switch||Distributed Switch||Yes|
Question 10- What is Long-Distance vMotion
Long distance vMotion can be referred as cross datacenter vmotion or cross country vmotion . VMware vSphere 6.0 adds functionality to migrate virtual machines over long distances. You can now perform reliable migrations between hosts and sites. To support long distance vmotion you required an Enterprise Plus license.
- A RTT (round-trip time) latency of 150 milliseconds or less, between hosts.
- Your license must cover vMotion across long distances. The cross vCenter and long distance vMotion features require an Enterprise Plus license.
- vMotion Network ( L2 network) .
- Virtual Machine Network
- vCenter Server 6.0 on Both Location
- Both vCenter Server instances must be time-synchronized.
- In vSphere Web Client, both vCenter Server instances must be in Enhanced Linked Mode and must be in the same vCenter Single Sign-On domain.
- vMotion network has at least 250 Mbps
Possible to move VMs on below scenarios
From VSS to VSS
From VSS to VDS
From VDS to VDS
Source and Destination VDS must be the same version.
In VSS , network labels used for the virtual machine port groups are consistent across hosts.
Question 10- What is Cross-vCenter Mixed-Version vMotion
Cross-vCenter Mixed-Version vMotion supported to clone or migrate a VM across different versions of vSphere 6.x, for example a vSphere 6.5 and a vSphere 6.0 Update 3 environment. you can even perform these operations across completely different vCenter Single Sign-On Domains
- This includes all VMware Cloud on AWS versions and vSphere 6.7.
- VMs that require encrypted vMotion cannot use vMotion with a destination vCenter version prior to vSphere 6.5 GA.
- VMs that use vSphere HA restart priority properties introduced in vSphere 6.5 cannot use vMotion and cold relocate with a destination vCenter version prior to vSphere 6.5 GA
- vSphere Encryption is not supported with cross vCenter Server vMotioning and cloning of virtual machines.
- Cross vCenter Server vMotion is not supported with 3rd party switches.
Question 11- What is Per-VM Enhanced vMotion.
Enhanced vMotion Compatibility (EVC) is a cluster feature that ensures CPU compatibility between hosts in a cluster, so that you can seamlessly migrate virtual machines within the EVC cluster. Starting with vSphere 6.7, you can also enable, disable, or change the EVC mode at the virtual machine level. The per-VM EVC feature facilitates the migration of the virtual machine beyond the cluster and across vCenter Server systems and data centers that have different processors. Unlike cluster-based EVC, you can change the per-VM EVC mode only when the virtual machine is powered off.
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