300+ TOP VMWARE Interview Questions and Answers

VMWARE Interview Questions for freshers experienced :-

1. What is VMware?

VMware is a virtualization technology-based software tool used to test various software virtually by making a virtual operating system. It is like using a different operating system simultaneously as your current OS. It develops virtualization software, which means creating an abstraction layer over computer hardware that allows the hardware elements of a single computer to be divided into multiple virtual computers, also called virtual machines (VMs).

2. What is the reason for using virtual machines instead of original hardware?

VM or Virtual machines allow us to operate multiple operating systems simultaneously from the same piece of hardware. Without virtualization, operating multiple systems like Windows and Linux would require two separate physical units. So it reduces the requirement to invest in additional units by splitting up a physical server into multiple servers.

3. What are the different types of virtualization available?

There are five types of visualizations available, they are:

• Desktop Virtualization.
• Application Virtualization.
• Server Virtualization
• Storage Virtualization.
• Network Virtualization

4. What is the server software VMware provides us?

VMware provides us with:

• VMware ESX Server,
• VMware ESXi Server, and
• VMware Server.

5. Name some VMware products.

• VMWARE MIRAGE,
• VMWARE PIVOTAL CONTAINER SERVICE,
• VMWARE PHOTON PLATFORM,
• VMWARE THINAPP,
• VMWARE VCLOUD NFV,
• VMWARE VCLOUD NFV OPENSTACK,
• VMWARE VCLOUD SUITE,
• VMWARE VREALIZE.

6. What is desktop virtualization? How does desktop virtualization work?

Desktop virtualization is a technology that simulates a workstation load to access a desktop from a connected device remotely or locally. This separates the desktop environment and associated application software from the physical client device used to access it.

Desktop virtualization works in many ways, but the basic two types of desktop virtualization are based on whether the operating system instance is local or remote.

• Local Desktop Virtualization: It denotes the operating system runs on a client device where all processing and workloads occur on local hardware. This desktop virtualization works when users don’t need a continuous network connection and can meet application computing requirements with local system resources. Although this requires processing to be done locally, you cannot use local desktop virtualization to share VMs or resources across a network to thin clients or mobile devices.

• Remote Desktop Virtualization: Remote desktop virtualization is a commonly used virtualization that operates in a client/server computing environment. It allows users to run operating systems from a server while all user interactions occur on a client device. The result is that IT departments have more centralized control over applications and desktops and can maximize the organization’s investment in IT hardware through remote access to shared computing resources.

7. What is network virtualization?

In virtualization technology, network virtualization is the process of combining network resources and network functionality into a single software-based administrative entity which is called a virtual network. It can combine multiple physical networks into one virtual software-based network, or it can divide one physical network into separate independent virtual networks.

8. Explain memory and storage virtualization?

Memory virtualization is the process of creating a memory pool by aggregating the resources of Random Access Memory (RAM) from individual systems in the data centre.

Storage virtualization is a process of taking information about all of the storage hardware resources on storage area networks. Logically this can be used to combine hardware resources from different networks and data centers.

9. What are the components of VMware infrastructure?

The major components of VMware infrastructure are:

• VMware ESX Server
• VirtualCenter Server
• VMware Infrastructure Client (VI Client)
• VMware Infrastructure Web Access (VI Web Access)
• VMware Virtual Machine File System (VMFS)
• VMware Virtual Symmetric Multi-Processing (SMP)
• VMware VMotion and VMware Storage VMotion
• VMware High Availability (HA)
• VMware Distributed Resource Scheduler (DRS)
• VMware Consolidated Backup (Consolidated Backup)
• VMware Infrastructure SDK

10. What is the requirement for running ESXi in the BIOS of the server?

Running ESXi in the BIOS requires the NX/XD bit to be enabled for the CPU in the BIOS in order to ensure the smooth installation of the software programs.

11. What does ESXi stand for?

ESXi stands for ESX Integrated.

VMware ESXi is a type-1, enterprise-class hypervisor which easily installs on to your server and divides itself into multiple virtual machines. It isn’t a software application, although it includes and integrates vital OS components, such as a kernel.

12. What is VMKernel? What is the VMkernel port used for?

The VMkernel is the interface between virtual machines (VMs) and the physical hardware of the system. The responsibility of VMkernel is scheduling CPUs, allocating memory and providing other hardware abstraction with other operating systems (OS) services.

Virtual machines cannot communicate with the ESXi server without VMKernel, so that’s why it’s very important for VMs.

VMkernel port, also called VMkernel adapter, is a type of VMkernel network interface that works as a service provider used by the ESXi host to communicate with the VMware-based infrastructure. These adapters or ports are created according to the type of services required by vMotion, Fault Tolerance, Management or perhaps vSAN etc.

13. What is VMotion? Why is it used?

VMotion could also be a key enabling technology for creating the dynamic, automated, and self-optimizing data centre.

We used VMware VMotion because it enables the live migration of running virtual machines from one physical server to a special one with zero downtime, continuous service availability, and complete transaction integrity.

14. What is Port-group?

VM port groups are how we will create logical rules round the virtual ports that are made available to VMs. It’s common to make a port group for every VLAN and network subnet that you simply want to present to your VMs.

15. What is vSwitch in VMware?

vSwitch is the software-based virtual networking switch used to connect virtual machines to the ESXi host & it also provides the connectivity between the virtual machines on that virtual switch. vSphere Standard Switch is referred to as vSwitch. Each ESXi host requires its own vSwitch.

16. How does vMotion work in the background?

The Virtual Machine Memory state is copied over the Vmotion Network from the source Host to the Target Host. Users still access the virtual machine and potentially update memory pages. A list of modified pages in memory is kept during a memory Bitmap on the source host.

17. What happens if VMotion fails?

VMotion will fail if the target host does not have enough memory to satisfy the reservation of the virtual machine. If you want to fix this, migrate the virtual machine to another ESXi host that can provide the guaranteed memory for the VM or reduce the memory reservation of the virtual machine.

18. What is the hypervisor and its types?

A hypervisor may be a virtualization layer that permits multiple operating systems to share one hardware host. Each operating system or Virtual Machine is allocated physical resources such as memory, CPU, storage etc by the host. There are two types of hypervisors.

• Hosted hypervisor – works as application i.e. VMware Workstation
• Bare-metal – is virtualization software i.e. VMvisor, Hyper-V which is installed directly onto the hardware and controls all physical resources.

19. We have got tons of features like VMotion, DRS, SMP, etc, but why do we like HA?

We’d like this because we want our services running without interruption. Assume like, for a couple of reasons if anyone of the ESX server within the cluster goes down suddenly, what happens to the virtual machines which are running thereon particular server? Do they continue to run or go down? Yes, they also go down. But with the help of VMware HA, these VM’s are often restarted immediately on the other ESX servers within an equivalent cluster. But here, you’ll get a downtime of 5 –10 mins because a server crash is an unexpected thing.

Intermediate VMware Interview Questions

If you are someone who already has a basic understanding of VMware, this section is helpful for you as it covers the intermediate VMware interview questions.

20. What architecture changes were seen between ESXi 4.1 and 5.0?

vSphere 5.0 involves a replacement HA architecture. HA has been rewritten from the bottom up to shed a number of those constraints that were enforced by AAM. HA, as a neighbourhood of 5.0, also mentioned as FDM (fault domain manager), introduces less complexity and better resiliency. From a UI perspective, not tons have changed, but there are tons under the covers that have changed. Though no more primary/secondary node concept as stated but a master/slave concept with an automated election process.

21. Is HA dependent on Vmware vCenter Server?

Yes. But only during the initial installation and configuration.

22. What is VM Monitoring status?

HA will usually monitor ESX hosts and reboot the virtual machine within the failed hosts within the opposite host within the cluster just in case of host isolation. Still, I want the HA to monitor Virtual machine failures also. Here the feature called VM monitoring status as a neighbourhood of HA settings.VM monitoring would restart the virtual machine if the VMware tools heartbeat didn’t receive within the specified time using Monitoring sensitivity.

23. What is VMware vSphere API and vSphere SDK?

VMware vSphere API may be a set of interfaces for managing vSphere. You can use the API to try to do most of the items the vSphere Client can do. The API is defined as SOAP Web Services with WSDL. The vSphere SDK could also be a group of libraries that support vSphere API, also as tools and samples that assist your development efforts. The vSphere SDK is additionally referred to as VI SDK, vCenter SDK, ESX SDK, etc. In most discussions, the vSphere API and vSphere SDK are used interchangeably.

24. What’s VMFS?

VMFS may be a block-level, high-performance clustered filing system for virtualization. It is often shared between multiple ESXi hosts or VMs and may simultaneously write and read data to and from one storage location.

25. What advantages does VMware filing system provide over the utilization of traditional file systems?

The advantages of the VMware filing system over the utilization of a traditional filing system are that the structure of VMFS makes it possible to store VM files in a single folder and simplifies VM administration. Traditional file systems authorize only one server to get read/write access to a storage resource. This guarantees that a VM works with only one ESXi server at a time.

26. What’s a VMware Data-store?

Data-stores are the storage containers for files. Generally, data-stores hide the specifics of every memory device and supply a consistent model for storing VM files. Data-stores are wont to hold virtual machine files, templates, ISO images etc.

27. What’s the difference between NFS and VMFS data-stores?

NFS may be a file-level filing system, while VMFS may be a block-level filing system. Once we create a VMFS Data-store, the VMFS filing system is made by the vSphere, but the NFS filing system is on the Storage side and is merely mounted and features a shared folder on the vSphere.

28. What’s iSCSI in VMware?

iSCSI may be a protocol which uses the TCP to move SCSI commands and also enables the utilization of the prevailing TCP/IP networking infrastructure as a cargo area Network.

29. What’s the default port employed by iSCSI during a VMware vSphere environment?

In a VMware vSphere environment, iSCSI uses TCP ports 860 and 3260 with higher-level names wont to address the objects within the protocol.

30. What’s multipathing in vmware?

In VMware, multipathing may be a process that permits you to employ quite one physical path that transfers data between the host and an auxiliary storage device. During a failure of any element within the SAN network, like a switch, adapter, or cable, ESXi can switch to a different physical path that doesn’t use the failed component.

31. What’s FCoE protocol?

Fibre Channel over Ethernet or FCoE may be a transport standard that takes Fibre Channel frames and encapsulates them within an enhanced Ethernet network. FCoE retains Fibre Channel upper-level protocol features like flow control and data integrity checking but not its cables and interfaces.

32. What’s the difference between FC and FCoE?

FCOE maps Fiber channels over full duplex Ethernet networks based on IEEE 802.3 standard. And therefore the other hand, Fiber Channel or FC may be a serial data transfer protocol and standard for high-speed enterprise-grade storage networking. It accelerates to 128 Gbps and delivers storage data over fast optical networks.

33. How does VMware measure IOPS?

VMware measures IOPs by these two formulas:

A. IOPS = 1/(Avg. Latency + Avg. Seek)(ms) (per Disk )

B. Total IOPS = IOPS * Total number of Disks.

34. What’s IOPS in VMware?

IOPS stands for Input/output Operations per Second and may be a common performance measurement to benchmark memory devices like hard disc drives, solid state drives and cargo area networks.

35. What’s the utilization of snapshots in VMware?

The VMware snapshot is used to preserve the state and data of the Virtual machine at the present point in time, so once you are done testing, you’ll quickly revert the VM back to the desired state. In VMware, VMware snapshots are easy and quick thanks to saving the state of a virtual machine before you test a software update, patch or other change.

36. What percentage sorts of snapshots are there in VMware?

As the perspective of files VMware snapshot are often four types:

1. Delta disk files
2. Flat file
3. Database file
4. Memory file

37. Are you able to restore a VM from a snapshot?

Yes, one can restore a snapshot in VMware by using the Revert and attend commands.

38. What’s ALUA storage?

ALUA stands for Asymmetric Logical Unit Access. ALUA may be a specific memory device capable of servicing I/O to a given LUN on two different storage processors but unevenly. Using ALUA, I/O to a given LUN are often sent to available ports on any of the SPs within the storage array.

39. What’s NUMA in VMware?

The full sort of NUMA is Non-uniform access. It’s a memory design utilized in multiprocessing, where the access time depends on the memory location relative to the processor. The biggest disadvantage is that the access of the CPU is usually the fastest when the CPU can access its local memory.

40. How do I enable NUMA in VMware?

There are thanks to enable NUMA in VMware which is:

• Configure one virtual machine to use hyper-threading with NUMA, add NUMA and VCPU.
• Click on the VM option then select Edit Settings.
• Now configure all virtual machines to use hyper-threading with NUMA. Add numa then configure PreferHT=1 for per-host advanced configuration file.

41. What’s vNUMA or Virtual NUMA?

vNUMA or virtual non-uniform access may be an access optimization technique for VMware virtual machines (VMs), which helps prevent memory-bandwidth bottlenecks. Virtual NUMA is particularly useful with large, multiple VMs during a vApp or high-performance virtual machines.

42. What’s a LUN in VMware? What’s the complete sort of LUN?

LUN stands for Logical Unit Number. LUN could also be a logical section of storage. A LUN is often one disk or multiple disks, and it can also be allocated from a disk pool or disk volume relying on the storage vendor’s terminology. A data store could also be a representation VMware uses for an area of storage that virtual machines can reside on.

43. Why is RDM employed in VMware?

RDM allows Virtual machines to bypass VMFS. VMware’s default storage management interface and access the memory device directly. In this manner, an RDM acts as a proxy for a raw LUN residing during a VMFS volume. RDM or Raw Device Mapping may be a mapping file that maps a LUN on to a VM.

44. What’s the difference between RDM and VMDK?

RDM is additionally referred to as a pass-through disk and may be a mapping file that acts as a proxy for a physical device like a LUN. On the opposite side, VMDK may be a file that appears as an uncompromising drive to the guest OS. Fundamentally it’s a virtual disk drive.

45. How to add RDM to VMware?

First, you’ve got to create the RDM pointer file, then attach the RDM to a virtual machine using the vSphere Client; Right-click the virtual machine you would like to feature an RDM disk, Click Edit Settings, Click Add, Select hard disc, Select Use an existing virtual disk.

46. What’s the first feature of VMware vSAN?

The primary feature of VMware vSAN is its work with VM storage policies to support a VM-centric approach to storage management.

47. What’s the difference between SAN and vSAN?

SAN leverages storage protocols like FCP and iSCSI while vSAN only works with ESXi hosts. Within the case of SAN, storage administrators are required to pre-allocate storage on different systems although vSAN automatically converts local storage resources into one storage pool.

48. What’s NAS in VMware?

The NAS or network-attached storage transport mode enables the virtual server agent proxy computer to read data directly from the network digital computer (NFS) without browsing an ESX host or transferring data over the local area network.

49. What’s vSphere replication NFC?

vSphere replication NFC is that the replication traffic was sent and received using the management interfaces of ESXi and VRA appliances. NFC (Network File Copy) traffic is employed to repeat VM replication data from the vSphere Replication Server appliance at the target site to the destination datastores.

50. What’s VMware VAAI?

VMware VAAI is hardware acceleration or hardware offload APIs which are a group of APIs to enable communication between VMware vSphere ESXi hosts and storage devices.

51. How do I know if VAAI is enabled?

To enabled VAAI steps are following,

1. In the vSphere Client inventory panel, click the host.
2. Click the Configuration tab, then click Advanced Settings under Software.
3. Check that these options are set to 1 (enabled).

52. What’s NFS in VMware?

NFS generally referred to as Network File Systems, may be file-level storage allocated by shared storage. Its network-attached storage will be shared through a cluster in vSphere. It also allows a user on a computer to access files over a network similar to local storage.

53. What’s the default number of ports configured with the virtual switch?

The default number of ports configured with the virtual switch is 128 ports.

54. What’s vDS in VMware?

The full form is vDS is VMware vSphere Distributed Switch which provides a centralized interface from which you’ll configure, monitor and administer virtual machine access switching for the whole data center. And it also provides support for advanced VMware vSphere networking features.

55. What’s a vSphere client?

The vSphere Client is application software that permits the management of a vSphere installation. The vSphere Client provides an administrator with access to the key functions of vSphere without the necessity to access a vSphere server directly.

56. What’s the max number of virtual machines per host?

Maximum number of virtual machines per host is 100.

57. What’s a host and cluster in VMware?

A Host is the virtual representation of the computing and memory resources of a physical machine running ESX Server, and a cluster may be a group of hosts.

58. What’s VMware auto deploy?

Auto Deploy is a process of VMware that stores the knowledge for the ESXi hosts to be provisioned in several locations. Information about the situation of image profiles and host profiles is initially laid out in the principles that map machines to image profiles and host profiles.

59. How does one automate a VM deployment in VMware?

Steps to automate a VM deployment in VMware:

1. Enter the vCenter IP address, username and password.
2. Select your vCenter platform.
3. Enter the registration details, and therefore the new specification name.
4. Enter the administrator password.

60. What are the 2 reasons why a virtual machine might fail to power on?

The two reasons for a virtual machine might fail to power on:

1. The virtual machine is running on an ESXi host which has an expired license.
2. The virtual machine is running on a data-store which has insufficient disc space for the .vswp file.

61. What’s VMware VUM?

VUM, also called VMware vSphere Update Manager, may be a tool that gives a patch management framework for VMware vSphere. IT administrators use VUM to patch and upgrade VMware ESXi hosts, VMware Tool, virtual hardware for virtual machines, and appliances.

62. What’s an appliance in VMware?

A virtual appliance consists of application software running on a preconfigured virtual machine with JeOS or simply enough OS needed to support the functions of the appliance.

63. What’s the utilization of vCenter server?

vCenter is employed to manage multiple ESXi hosts, virtual machines and every one dependent component from one centralized location.

64. What are the most components of vCenter server architecture?

The vCenter Server architecture consists of three main components which are vSphere Web Client, vCenter Server Database and vCenter Single Sign-On.

65. What are the services in vCenter server?

The vCenter Server services are vCenter Server, vSphere Web Client, Inventory Service, vSphere Auto Deploy, vSphere ESXi Dump Collector, VMware vSphere Syslog Collector on Windows and VMware Sphere Syslog Service for the vCenter Server Appliance.

66. What are the extra modules of VMware vCenter server?

VMware vCenter server additional modules are vCenter Update Manager, vCenter Converter, and vCenter Guided Consolidation Service.

67. How do I export VM from vCloud director?

The steps to export VM from vCloud director:

1. Navigate to the organization you would like to export from.
2. Click on Catalogs.
3. Click on vApp Templates.
4. Right-click on the VM that you simply wish to export, and choose Download.
5. Click on Browse, and choose a folder and a reputation to store the OVF export

68. Which cloud service does VMware vCloud air provide?

vCloud Air provides three Infrastructure as a Service(IaaS) subscription service types- dedicated cloud, virtual private cloud, and disaster recovery.

69. What’s VMware VADP?

VMware VADP may be a VMware vStorage API that backs up and restores vSphere virtual machines. VADP replaces the VMware Consolidated Backup (VCB) framework, this offloads backup processing from ESX hosts and allows each ESX host to run more VMs.

70. What does MOB in VMware stand for?

MOB in VMware stands for Managed Object Browser.

71. How do I disable Storage DRS for the Data-store?

The steps are:

1. Browse to the data-store cluster within the vsphere Client.
2. Click the Configure tab and click on Services.
3. Select Storage DRS and click on Edit.
4. Select activate vSphere DRS and click on OK.

An optional step is to disable only I/O-related functions of Storage DRS, leaving space-related controls enabled then perform the subsequent steps.

72. What do you mean by clone & template in VMware? What is the difference between the two? 

Clone VMware: Clone virtual machines are the identical copy of the parent virtual machine; however the clone virtual machine and parent virtual machine will have different MAC addresses and UUIDs. Any changes done on a cloned virtual machine will not affect the parent virtual machine and vice-versa.

Template VMware: Template VMware the master copy or golden image of virtual machine that is used to provision virtual machines. This image can be later used to clone multiple virtual machines.

Clone VMware	Template VMware
Create the exact copy of the parent virtual machine that can work independently	It is a master copy of a VM with basic configuration and can’t work independently
The cloned VM can’t be converted back to the parent VM or original VM	Template VMware can be converted back to virtual machine and updated the latest configuration before converting back to template for future VM deployment
For deploying large numbers of VM it is not recommended	For deploying large numbers of VM it is recommended
Clone VM can we turned on/off	Template can’t be turned on/off or edit it
Powered on VM can we cloned	Powered on VM can’t be used to create templates

73. What are VMware HA and VMware FT? What is the difference between the two?

VMware HA: VMware HA (High Availability) works on cluster level. By pooling virtual machines and hosts resides into a cluster. Virtual machines running on failed hosts are forced to restart on alternate hosts.

VMware FT: Vmware FT (Fault Tolerance) works on VM Level. In this a secondary virtual machine is created and maintained as identical to the primary virtual machine and it can be replaced when ESXi hosts fail to provide continuous availability of virtual machines. It is a complete copy of a virtual machine including storage, computation and memory.

VMware HA	VMware FT
VMware HA is enabled per cluster	VMware FT is enabled per Virtual Machine
VMware HA works on cluster level	VMware FT works on VM level
In case of failure the HA system will restart and power on VM on another host	In case of failure the FT system will start secondary host in case the lost of primary host by providing fast backup and continuous availability and reduces downtime

74. How many CPUs can be used for a VM in FT in vSphere 7.0?

In VMware vSphere 7.0, we can use up to 8 vCPUs with VMware vSphere Enterprise Plus license.

75. Explain Fault Tolerance logging traffic.

Fault tolerance logging traffic is considered to be the second network requirement. For syncing the data between primary VMs and secondary VMs fault tolerance applies FT logging.

76. Differentiate between vSphere and vCenter.

vSphere	vCenter
vSphere is a complete infrastructure for virtualization	vCenter is a centralized and extensible platform
It is complete infrastructure for virtualization	It is a centralized and extensible platform
It allows IT team to build reliable and resilient infrastructure	It allows IT team to automate and deliver a virtual infrastructure
The initial release of vSphere was April 21, 2009	The initial release of vCenter was December 5, 2003

77. Will FT work if the vCenter server goes down?

Fault tolerance does not require vCenter to be online once configured, due to this no fault tolerance between primary and secondary will occur when vCenter is down.

78. What do you understand about Promiscuous mode?

Promiscuous mode is used for monitoring traffic. In the Promiscuous mode, all the network data packets can be viewed and accessed by all the network adapters operating in this mode. It is a network security, monitoring, and administration method that allows any network adapter configured on a host system to access all network data packets.

79. What do you mean by cold and hot migration?

Cold Migration: In this migration, the powered-off VM, along with its configuration and data, is migrated from one host to another host. The VMs can be migrated manually, or one can set up scheduled tasks to perform this migration.

Hot Migration: In this migration, the powered-on VM is migrated from one host to another. This is also known as live migration because there is no need to shut down the virtual machine.

80. What is the difference between virtual desktop and remote desktop?

Remote Desktop: The remote desktop program allows a computer that is located at a different location and interacts with the desktop as if they are accessing them physically, sitting in front of that device. Its solution is best for people who want to access their computers if they are away from their usual workplace. Also, it is beneficial for the technician who wants to fix any issues remotely by taking the remote console of that system.

Virtual Desktop: Virtual Desktop and Remote Desktops offer similar functionality – under the surface, there are a few significant differences. Virtual desktops provide a pre-configured image of operating systems or applications – separate from the device used to access them. Over the internet, any endpoint device – be it a laptop, tablet, or smartphone can be used to access the virtual desktop.

81. How can I differentiate between virtual machine port groups and VMkernel ports?

The VMKernel port provides connectivity to the host, and it handles the traffic like vMotion, Fault Tolerance traffic, and management. The IP address is assigned to the Virtual Kernel Adapter (VMK) of the VMKernel port group. The Virtual machines are connected to the VM port group.

One of the important differences is that a Virtual Machine port group is just passing your garden variety virtual machine traffic, and a VMKernel port group is passing traffic specific to VMware vSphere.

82. What’s the difference between VMFS and NFS?

VMFS (Virtual Machine File System): VMFS is a block-level file system that is used to store virtual machine files. In vSphere 6.0, it can also store large files up to 64TB in size.

NFS (Network File System): NFS is a distributed file system protocol that was first developed by Sun Microsystems in 1984. It has a client/server architecture, which contains a client program, server program, and protocol that helps to communicate between the client and the server. It helps the user to access the data and files easily over the network.

83. What do you understand about RDM?

The Raw Device Mapping (RDM) files are contained in VMFS and act as proxies for raw physical devices. This helps virtual machines access logical unit numbers (LUNs) directly. The RDM contains metadata used for managing and redirecting disk access to the physical device.

Basic VMWARE Questions with Answers Pdf Download

1. What is VMware?
VMware, Inc. is an American company that provides cloud and virtualization software and services, and claims to be the first to successfully virtualize the x86 architecture commercially. Founded in 1998, VMware is based in Palo Alto, California.

VMware provides different applications and software for virtualization. VMware products are categorized into two levels, desktop applications, and Server applications.

2. What is virtualization?
Virtualization is a proven software technology that makes it possible to run multiple operating systems and applications on the same server at the same time. It’s transforming the IT landscape and fundamentally changing the way that people utilize technology.

3. What do you understand by Virtual Machine?

• A virtual computer systems is known as “virtual machine” (VM): a tightly isolated software container with an operating system and application inside.
• Each self-contained VM is completely independent. Putting multiple VMs on a single computer enables several operating systems and applications to run on just one physical server, or “host”.

4. What is hypervisor?
A hypervisor is a program that enables multiple operating systems to share a single hardware host. Each operating system has the host’s processor, memory and other resources all to itself. The hypervisor controls the resources and host processor, allocating what is required for each operating system in turn and make sure that the guest operating system cannot disrupt each other.

5. What are the main advantage of VMWare Vsphere?

• Ensure business continuity and always available IT
• Reduce IT hardware and operating costs
• Improve application quality
• Enhanced security and data protection

6. What is Data Store?
Data store represents a storage location for virtual machine files. It can be a Virtual Machine File System (VMFS) volume, a directory on Network Attached Storage, or a local file system path.

7. What is VMware DRS?
VMware DRS stands for Distributed Resource Scheduler; it dynamically balances resources across various host under cluster or resource pool. It enables users to determine the rules and policies which decide Define How virtual machines deploy resources, and these resources should be prioritized to multiple virtual machines.

8. When using ESXi hypervisor architecture, Define How to monitor hardware on vSphere host?
vSphere supports CIM API and SNMP v2, without installing agents to enable hardware monitoring. Hardware monitoring tools can monitor through vCenter console and major hardware provided by OEM vendors.

9. Explain what is VMware DPM?
VMware Distributed Power Management (DPM) is a pioneering new feature of VMware DRS that continuously monitors resource requirements in a VMware DRS cluster. When resource requirements of the cluster decrease during periods of low usage, VMware DPM consolidates workloads to reduce power consumption by the cluster. When resource requirements of workloads increase during periods of higher usage, VMware DPM brings powered-down hosts back online to ensure service levels are met.

10. When you visit certain Web sites, the request is “connection was reset” the report, then Define what is the principle of connection is reset?
The nature of the connection is reset, because it has received a TCP Reset packet damage connected

11. VMware ESX is still providing support for the architecture?
VMware will follow VMware vSphere support policy to continue to provide technical support for ESX architecture.

12. How can I evaluate VMware vSphere?
The easiest way to evaluate VMware vSphere is to download and install the free vSphere Hypervisor version. In addition, you can also use vSphere assessment .

13. When using the ESXi architecture, Update Manager whether to repair my vSphere host?
VMware vCenter Update Manager will be updated to run ESXi host. In addition to VMware Update Manager environment provides not installed the update utility.

14. What is the ESXi Shell?
ESXi Shell is a command-line interface to run diagnostics and repair of vSphere ESXi hosts. ESXi Shell by DCUI or through vCenter Server to enable and disable, and can also be accessed remotely via SSH. For more information, see the ESXi Management page.

15. What are the advantage and disadvantages of VMWare workstation?
Advantage:

• VMware Workstation virtual machine capability, performance and physical isolation is very good!
• VMware Workstation features a very comprehensive, computer professionals tend to use!
• VMware Workstation is simple interface for users of various fields of computer!

Disadvantages:

• VMware Workstation bulky, longer installation time-consuming!
• VMware Workstation occupy a larger physical machine resources when using!

16. Can we do vMotion between two datacenters ? If possible Define How it will be?
Yes we can do vMotion between two datacenters, but the mandatory requirement is the VM should be powered off.

17. What is VC agent? and Define what service it is corresponded to? Define what are the minimum req’s for VC agent installation ?

1. VC agent is an agent installed on ESX server which enables communication between VC and ESX server.
   The daemon associated with it is called vmware-hostd , and the service which corresponds to it is called as mgmt-vmware, in the event of VC agent failure just restart the service by typing the following command at the service console ” service mgmt-vmware restart ”
2. VC agent installed on the ESX server when we add it to the VC, so at the time of installtion if you are getting an error like ” VC Agent service failed to install “, check the /Opt size whether it is sufficient or not.

18. How can you edit VI Client Settings and VC Server Settings ?
Click Edit Menu on VC and Select Client Settings to change VI settings
Click Administration Menu on VC and Select VC Management Server Configuration to Change VC Settings

19. Define what are the files that make a Virtual Machine ?
.vmx – Virtual Machine Configuration File
.nvram – Virtual Machine BIOS
.vmdk – Virtual Machine Disk file
.vswp – Virtual Machine Swap File
.vmsd – Virtual MAchine Snapshot Database
.vmsn – Virtual Machine Snapshot file
.vmss – Virtual Machine Suspended State file
.vmware.log – Current Log File
.vmware-#.log – Old Log file

20. What are the devices that can be added while the virtual Machine running
In VI 3.5 we can add Hard Disk and NIC’s while the machine running.
In vSphere 4.0 we can add Memory and Processor along with HDD and NIC’s while the machine running

21. How to set the time delay for BIOS screen for a Virtual Machine?
Right Click on VM, select edit settings, choose options tab and select boot option, set the delay Define How much you want.

22. What is a template ?
We can convert a VM into Template, and it cannot be powered on once its changed to template. This is used to quick provisioning of VM’s.

23. What to do to customize the windows virtual machine clone,?
copy the sysprep files to Virtual center directory on the server, so that the wizard will take the advantage of it.

24. What to do to customize the linux/unix virtual machine clone,?
VC itself includes the customization tools, as these operating systems are available as open source.

25. Does cloning from template happens between two datacenters ?
Yes.. it can, if the template in one datacenter, we can deploy the vm from that template in another datacenter without any problem.

26. What are the common issues with snapshots? Define what stops from taking a snapshot and Define How to fix it ?
If you configure the VM with Mapped LUN’s, then the snapshot failed. If it is mapped as virtual then we can take a snapshot of it.
If you configure the VM with Mapped LUN’s as physical, you need to remove it to take a snapshot.

27. What are the settings that are taken into to consideration when we initiate a snapshot ?

• Virtual Machine Configuration (Define what hardware is attached to it)
• State of the Virtual Machine Hard Disk file ( To revert back if needed)
• State of the Virtual Machine Memory (if it is powered on)

28. What are the requirements for Converting a Physical machine to VM ?

1. An agent needs to be installed on the Physical machine
2. VI client needs to be installed with Converter Plug-in
3. A server to import/export virtual machines

29. What is VMWare consolidated backup ?
It is a backup framework, that supports 3rd party utilities to take backups of ESX servers and Virtual Machines. Its not a backup service.

30. To open the guided consolidation tool, Define what are the user requirements ?
The user must be member of administrator, The user should have “Logon as service” privileges – To give a user these privileges, open local sec policy, select Logon as service policy and add the user the user should have read access to AD to send queries

31. Explain the physical topology of Virtual Infrastructure 3 Data Centre?
a typical VMware Infrastructure data center consists of basic physical building blocks such as x86 computing servers, storage networks and arrays, IP networks, a management server and desktop clients.

32. How do you configure Clusters, Hosts, and Resource Pools in VI3?
A cluster is a group of servers working together closely as a single server, to provide high availability, load balancing and high performance. A host is a single x86 computing server with individual computing and memory resources. Resource pools are allocation of the available resources in to pieces for the proper distribution.

33. What are resource pools & Define what’s the advantage of implementing them?
A VMware ESX Resource pool is a pool of CPU and memory resources. Inside the pool, resources are allocated based on the CPU and memory shares that are defined. This pool can have associated access control and permissions. Clear management of resources to the virtual machines.

34. Explain why VMware ESX Server is preferred over Virtual Server or Workstation for enterprise implementation?
For better resource management as it has a virtualization layer involved in its kernel, which communicates with the hardware directly.

35. In Define what different scenarios or methods can you manage a VI3 ?
Using the Virtual Infrastructure Client we can manage one esx server, using virtual center we can manage more than 1 esx server.. and also we can use service console to manage it.
http://searchvmware.techtarget.com/tip/0,289483,sid179_gci1280576_mem1,00.html

36. Explain the difference between access through Virtual Infrastructure Client (vi client), Web access, Service Console access(ssh) ?
Using VI Client we can access the ESX server as well as Virtual Center Server also, here we can use unix type of authentication or windows type authentication. But to access the service console, we should use unix type of authentication preferably even though we can access the service console through ad authentication using esxcfg-auth, but it does not support all functions to work on, all the functions are available only with root account which is based on red hat Linux kernel. Using the web access also we can manage virtual center as well as a single host. But all the enterprise features are not supported.
Console access to the Service Console
The disadvantages to this mode are
you must be at the console (or connect using an IP KVM) and

you must know Linux to accomplish your task (no GUI).

SSH to the Service Console

You can SSH to the console prompt of an ESX server and receive the same Linux text console access as I sDefine Howed above. Telnet is not allowed. To use this method, the ESX server must be working on the network and you must have an SSH client on your PC to connect. Again, in this mode, you don’t get a GUI interface.

VMware Virtual Infrastructure (VI) Web Access to the ESX Server

This is the VMware VI Web Access interface. The benefit to using this is that you get a GUI client for your ESX server without having to install a client on your local machine. The downside to the web interface is that you can only perform basic ESX functions like controlling existing machines (start/stop/pause) and console remote access. You cannot add new VMs, work with VM storage, or VM networks. Still, this is a great interface if you just need to check the status of your ESX VMs, restart a VM, or use console remote control.

VMware Virtual Infrastructure Client (VI Client) to the Server

The benefits to the VI client are that you have full access to do Define whatever is needed on the ESX Server and you get a GUI client to do it in. The only downside is that you must install the VI client application to do this. Define However, the installation is negligible and the VI client is the absolute best way to administer your ESX Server.

VMware Virtual Infrastructure Client (VI Client) to the Virtual Center Server (VC Server)

From this VI VC interface, you can manage all ESX servers, VM storage, VM networks, and more. Virtual Center, of course, is an optional product that requires additional licenses and hardware.

37. Explain advantages or features of VMware Virtual Machine File System (VMFS) ?
It’s a clustered file system, excellent support for sharing between ESX servers in a cluster.

Features

• Allows access by multiple ESX Servers at the same time by implementing per-file locking. SCSI Reservations are only implemented when LUN meta data is updated (e.g. file name change, file size change, etc.)
• Add or delete an ESX Server from a VMware VMFS volume without disrupting other ESX Server hosts.
• LVM allows for adaptive block sizing and addressing for growing files allows you to increase a VMFS volume on the fly (by spanning multiple VMFS volumes)
• With ESX/ESXi4 VMFS volumes also can be expanded using LUN expansion
• Optimize your virtual machine I/O with adjustable volume, disk, file and block sizes.
• Recover virtual machines faster and more reliably in the event of server failure with Distributed journaling.

Limitations

• Can be shared with up to 32 ESX Servers.
• Can support LUNs with max size of 2TB and a max VMFS size of 64 TB as of version 4 (vSphere).
• “There is a VMFS-3 limitation where each tree of linked clones can only be run on 8 ESX servers. For instance, if there is a tree of disks off the same base disk with 40 leaf nodes in the tree, all 40 leaf nodes can be simultaneously run but they can only run on up to 8 ESX hosts.”
• VMFS-3 limits files to 262,144 (218) blocks, which translates to 256 GB for 1 MB block sizes (the default) up to 2 TB for 8 MB block sizes.

38. What are the types of data stores supported in ESX3.5 ?
iSCSI datastores, FC SAN datastores, Local VMFS, NAS and NFS

39. How can you configure these different types of datastores on ESX3.5 ?
If we have FC cards installed on the esx servers, by going to the storage option, we can scan for the luns.

40. What is Vmware Consolidate Backup (VCB) ? Explain your work exposure in this area ?
VMware Consolidated Backup is a backup framework, which enables 3rd party tools to take backups. VCB is used to help you backup your VMware ESX virtual servers. Essentially, VCB is a “backup proxy server”. It is not backup software. If you use VCB, you still need backup software. It is commonly installed on its own dedicated Windows physical server.

Here are the benefits of VMware’s VCB:

• Centralize backups of VMware ESX Virtual Servers
• Provide file-level backups of VMware ESX Virtual Servers – both full and incremental (file level backup available to only Windows guests)
• Provide image-level backups
• Prevent you from having to load a backup agent on every Virtual Machine
• Prevent you from having to shutdown Virtual Machines to get a backup
• Provides LAN-Free backup because the VCB server is connected to the SAN through your fibre channel adaptor
• Provides centralized storage of Virtual Server backups on the VCB server, that is then moved to your backup tapes through the 3rd party backup agent you install
• Reduces the load on the VMware ESX servers by not having to load a 3rd party backup agent on either the VMware ESX service console or on each virtual machine.
• Utilizes VMware Snapshots
  Basically, here is Define How VCB works:
• If you are doing a file level backup, VCB does a snapshot of the VM, mounts the snapshot, and allows you to backup that mounted “drive” through VCB to your 3rd party backup software
• If you are doing an image level backup of the VM, VCB does a snapshot of the VM, copies the snapshot to the VCB server, unsnaps the VM, and allows you to backup the copied snapshot image with your 3rd party backup software.

41. How do you configure VMware Virtual Centre Management Server for HA & DRS ? Define what are the conditions to be satisfied for this setup?
HA & DRS are the properties of a Cluster. A Cluster can be created only when more than one host added, in that case we need to configure HA & DRS as well to provide High Availability and Load balancing between hosts and for the virtual machines.

42. What is VMware DRS?
VMware DRS stands for Distributed Resource Scheduler; it dynamically balances resources across various host under a cluster or resource pool. It enables users to determine the rules and policies which decide how virtual machines deploy resources, and these resources should be prioritized to multiple virtual machines.

43. What SAN or NAS boxes have you configured VMware with ? Define How did you do that ?
Storage team will provide the LUN information, with that we will add those LUNs to ESX hosts from VM storage.

44. What kind of applications or setups you have on you Virtual Machines ?
Exchange server and Share Point, but these are for DEMO purposes, Cirtrix presentation servers etc.

45. Have you ever faced ESX server crashing and Virtual Centre Server crash? Define How do you know the cause of these crashes in these cases ?
Please send me the answer if anyone knows about this, I will update . iqatts@gmail.com

46. Will HA work if Virtual Center Server is down ?
A1) HA continues to work if VC is down – the agents are initially configured by virtual center, but HA operations are controlled by local agents on ESX. VC does NOT monitor the ESX servers for HA. ESX servers monitor each other.
DRS do not work while VC is down.

A2) For DRS, the config and logic is completely in VC.
For HA, only the config is in VC. The logic is in the service consoles, and that’s where the reaction is coming from. VC will notice the HA reaction afterwards when it connects to the service consoles the next time.
No, Why because all these futures are comes with Virtual Center only.

47. What are the situations which triggers vMotion automatically?
Resource Contention between virtual machines (DRS)
Distributed power management
Please send me the answer if anyone knows about this; I will update . iqatts@gmail.com

48. What is DRS/HA/DPM/dvSwitch/FT/vApps/vSafe/vShields ?
DRS : Distributed Resource Scheduling
HA : High Availability
DPM : Distributed Power Management
dvSwitch : Distribute vSwitch – It’s a new feature introduced in vSphere4.0
FT : Fault Tolerance for Virtual Machines – it’s a new feature introduced in vSphere4.0
vApps : vApp is a container same as resource pool, but it is having some features of virtual machines, a vApp can be powered on or powered off, and it can be cloned too.
http://communities.vmware.com/message/1308457#1308457
vmSafe : VMsafe’s application programming interfaces are designed to help third-party vendors create virtualization security products that better secure VMware ESX, vShield Zones is a security tool targets the VMware administrator.

vShield : VShield Zones is essentially a virtual firewall designed to protect VMs and analyze virtual network traffic. This three-part series describes vShield Zones, explains Define How to install it and provides useful management tips. To begin, let’s get started with the basics: Define what vShield Zones is and Define How it works.

http://searchvmware.techtarget.com/tip/0,289483,sid179_gci1363051_mem1,00.html

49. What are the requirement for FT ?
http://communities.vmware.com/thread/209955

50. What are the differences between ESX and ESXi ?
ESX is an OS with full features of virtualization, ESXi is a limited features OS with 32MB image.

51. 64-bit hypervisor – Although not everyone realized it, the hypervisor in ESX Server 3.5 was 32-bit. As a result, ESX Server 3.5 couldn’t take full advantage of today’s more powerful 64-bit hardware platforms. ESX Server 4.0 uses a native 64-bit hypervisor that provides significant performance and scalability enhancements over the previous versions. Define However, the new hypervisor does require a 64-bit hardware platform.

52. Increased VM scalability – ESX Server 4.0’s new 64-bit architecture provides significant increases in scalability. ESX Server 4.0 supports virtual machines (VMs) with up to 255GB of RAM per VM. In addition, the vSphere 4.0 Enterprise Plus edition provides support for up to 8-way virtual SMP per VM. The other editions support up to 4-way virtual SMP. These gains are available on both Windows and Linux guests.

53. Hot add CPU, RAM, and virtual disks – This important enhancement in vSphere 4.0 is designed to create a dynamic IT infrastructure through the ability to add CPU, RAM, and virtual disks to a running VM. The hot add capability lets you dynamically increase your VMs’ performance during periods of high resource demands.

54. Thin provisioning – This feature is nothing new to Microsoft virtualization users; vSphere now offers a thin-provisioning feature that’s essentially the equivalent of Hyper-V’s dynamic disks. Thin provisioning lets you create and provision a Virtual Hard Disk (VHD), but the host uses only the amount of storage that’s actually required by the VM rather than using the VHD’s allocated size.

55. VMware Fault Tolerance – Fault Tolerance is a new high-availability feature in vSphere 4.0. Fault Tolerance works only between two systems. It uses a technology called vLockstep to provide protection from system failure with absolutely no downtime. VMware’s vLockstep technology keeps the RAM and the virtual processors of two VMs in sync at the instruction level.

56. vNetwork Distributed Switch— vSphere 4.0’s vNetwork Distributed Switch lets you create and share network configurations between multiple servers. The vNetwork Distributed Switch spans multiple ESX Server hosts, letting you configure and manage virtual networks at the cluster level. It also lets you move network configuration and state with a VM when the VM is live migrated between ESX Server hosts.

57. IPv6 support – Another enhancement in vSphere 4.0 is support for IPv6. Many organizations are planning to move to IPv6. vSphere’s IPv6 support lets customers manage vCenter Server and ESX Server hosts in mixed IPv4/IPv6 network environments.

58. vApps—vApps essentially lets you manage as a single entity multiple servers that comprise an n-tiered application. Using vApps, you can combine multiple VMs, their interdependencies, and their resource allocations together as a unit. You can manage all the components of the vApps as a single unit, letting you power off, clone, and deploy all the vApps components in the same operations.

59. vSphere Host Update Utility—The new vSphere Host Update Utility lets you centrally update your ESXi and ESX Server 3.0 and later hosts to ESX Server 4.0. The UI displays the status of the remote updates in real time.

60. VMware vShield Zones—VMware’s new vShield Zones let customers enforce network access protection between VMs running in the virtual data center. The vShield Zones feature lets you isolate, bridge, and firewall traffic across vCenter deployments.

61. Which are the traffic shaping options available to configure?

62. What is promiscuous mode ?
If the promiscuous mode is enabled for a switch, the traffic sent that switch will be visible to all vm’s connected to that switch. I mean, the data will be broadcasted.

63. What makes iSCSI and FC diffrent ?
Addressing Scheme, iSCSI relies on IP and FC not, and the type of transfer of data also. In FC the data transferred as blocks, in iSCSI the data transferred as files. The cabling also, FC uses Fibre cable and iSCSI uses RJ45.

64. What is the format for iSCSI addressing ?
IP Address

65. VM’s Task Manager sDefine Hows performance normal, But vCenter reports high resource utilization, Define what is the reason ?
Search KEY WORDS : VM’s performance normal, vCenter reports high resource utilization

http://communities.vmware.com/message/897975

66. What are the different types of memory management tricks available under ESX ?
http://en.wordpress.com/tag/esx-memory-management/
http://www.cs.northwestern.edu/~fabianb/classes/cs-443-s05/ESX.pps

67. What is vmmemctl ?
http://pubs.vmware.com/vi3/resmgmt/wwhelp/wwhimpl/common/html/wwhelp.htm?context=resmgmt&file=vc_advanced_mgmt.11.24.html

68. How we can list pNICs & status using command line ?
ifconfig –a

69. What is resource pool ? Define what are the use of it ?
A resource pool is a logical abstraction for flexible management of resources. Resource pools can be grouped into hierarchies and used to hierarchically partition available CPU and memory resources.

70. How HA works.
VMware HA provides high availability for virtual machines by pooling them and the hosts they reside on into a cluster. Hosts in the cluster are monitored and in the event of a failure, the virtual machines on a failed host are restarted on alternate hosts.

71. Is HA dependent on virtual center
(Only for Install)

72. What is the Maximum Host Failure allowed in a cluster
(4)

73. How does HA know to restart a VM from a dropped Host
(storage lock will be removed from the metadata)

74. How many iSCSI targets will ESX support
8 for 3.01, (64 for 3.5)

75. How Many Fiber Channel targets
(256) (128 on Install)

76. What is Vmotion
(ability to move running vm from one host to another)

77. What is virtual SMP –
when and why should you give a vm multiple vCPUs – part of their answer whould be that best pracrtice is to start with a single vCPU because of you can run into perfomance issues do to CPU scheduling

78. What version of Linux kernel does ESX run
if they are truly experienced they should say ESX is not Linux and does not use a Linux kernel – and give them an extra poijnt if they explain that the service console runs a modified version of Red Hat Ent 3 –

79. Does HA use vmotion?
the answer is no – vm stops and restarts on ESX other host

80. What is the different when you use viclient connect to VC and directly to ESX server itself.
When you connect to VC you manage ESX server via vpxa (Agent on esx server). Vpxa then pass those request to hostd (management service on esx server). When you connect to ESX server directly, you connect to hostd (bypass vpxa). You can extend this to a trobleshoot case, where connect to esx see one thing and connect to VC see another. So the problem is most likely out of sync between hostd and vpxa, “service vmware-vpxa restart” should take care of it.

81. What was the most difficult VMWare related problem/issue you faced in a production environment and Define what were the specific steps you took to resolve it?
HA issues – because of dns problems, the hosts are unable to communicate together. Corrected by adding all servers ip’s in each server’s /etc/hosts file
VM was not powered up – because the swap file was locked by another host, when I try to power on the vm its not powering up. After releasing the lock its powered on.

82. When was the last time you called VM Support and Define what was the issue?
Licensing related issues.

83. What was the most performance intensive production app that you supported in VMware and Define what were the some of the challenges that it posed?
In exchange sharepoint demo project, getting lot of VLAN issues. (its my experience, you can say yours)

84. How would you determine that a perf intensive app is a good candidate?
Spefically Define what tools would you use to identify candidates. Specifically inside those tools Define what metrics would you use?
Please send me the answer if anyone knows about this; I will update. iqatts@gmail.com

85. What is yor philosophy on Define How much of the data center can be virtualized?
(If the interviewer wants max virtualization, but the interviewee is not convinced that this is a good idea, this could be a deal breaker)
Please send me the answer if anyone knows about this; I will update. iqatts@gmail.com

86. What is your opinion on the virtualization vendors (MS vs VM vs Citrix vs etc) and why?
(Just trying to figure out if the candidate is keeping up with this ever changing virtualization market)
Please send me the answer if anyone knows about this; I will update . iqatts@gmail.com

87. What is Virtual Desktop Infrastructure?
Virtual Desktop Infrastructure which also known as VDI allows you to host the desktop operating system on the centralized window server in a data center. It is also known as server-based computing as it is the variation on the client-server computing model.

88. What is Cluster in VMware?
Cluster in VMware is a logical grouping of multi ESXi hosts. It allows you to add or delete the host from the cluster. It also provides a feature like HA, DRS, on the cluster.

89. What are notable files that represent a VM?
.vmx – configuration settings for VM
.vmxf – configuration settings used to support an XML-based VM configuration API
.vmtx – configuration settings for a Template VM (replaces the .vmx file)
.vmdk – virtual disk file. (Note: if a thick disk is used, a –flat.vmdk file that represents the actual monolithic disk file will exist but will be hidden from the vSphere Client.)
.nvram – non-volatile memory (BIOS)
.vswp – swap file used by ESX/ESXi per VM to overcommit memory, i.e. use more memory than physically available. This is created by the host automatically when powering on a VM and deleted (default behavior) when powering off a VM. Swap files can remain and take up space if a host failed prior to shutting down a VM properly. Normally the swap file is stored in the location where the VM configuration files are kept; Define However the location can be optionally located elsewhere—for example, locally for performance reasons and if using NAS/NFS, local swap should be used.
.vmss – suspend file (if placed into suspend power mode)
.vmsd – for snapshot management
.vmsn – snapshot file

90. Host Profiles
Define what licensing is required for Host Profiles? Available with vSphere Enterprise Plus edition.

91. Can Host Profiles work with ESX/ESXi 3.x hosts?
No. Only starting with ESX/ESXi 4.0.

92.Can Host Profiles be used with a cluster running both ESX and ESXi hosts?
Yes, but remember to use an ESX host and not an ESXi host to create a profile for use.
In theory, Host Profiles should work with mixed host clusters, as it translates ESX to ESXi, but be careful as there are enough differences between ESX and ESXi that can lead you to make self-inflicted errors when applying Host Profiles. The easiest method is to create clusters that are homogeneous and maintain two different profiles for these two types of clusters.

93.Can Host Profiles work when using the Cisco Nexus 1000v?
No, because Host Profiles was designed with the generic vNetwork Distributed Switch. The Cisco Nexus 1000v switch gives administrators finer-grained control of the networking beyond Define what Host Profiles can apply.

94. What are host profiles?
A set of best practiced configuration rules, which are can be applied to entire cluster or to an individual host. So that all the hosts in sync with each other, this will avoid vmotion, drs and ha problems.

95. What are the available Storage options for virtual machines ?
Raw device mappings, VMFS
http://searchvmware.techtarget.com/tip/0,289483,sid179_gci1318776_mem1,00.html

96. What are the differences between Virtual and Physical compatibility modes when mapping the Raw Devices to virtual machines?
You can configure RDM in two ways:
Virtual compatibility mode—this mode fully virtualizes the mapped device, which appears to the guest operating system as a virtual disk file on a VMFS volume. Virtual mode provides such benefits of VMFS as advanced file locking for data protection and use of snapshots.

Physical compatibility mode—this mode provides access to most hardware characteristics of the mapped device. VMkernel passes all SCSI commands to the device, with one exception, thereby exposing all the physical characteristics of the underlying hardware. In this mode, the mapping is done as follows, when we create a mapping, the configuration stored in a file and that file is stored with the vm files in datastore. This file points to the raw device and makes it accessible to the vm.

97. What are RDM Limitations?
RDM limitations

1. There are two types of RDMs: virtual compatibility mode RDMs and physical compatibility mode RDMs.
2. Physical mode RDMs, in particular, have some fairly significant limitations:
3. No VMware snapshots
4. No VCB support, because VCB requires VMware snapshots
5. No cloning VMs that use physical mode RDMs
6. No converting VMs that use physical mode RDMs into templates
7. No migrating VMs with physical mode RDMs if the migration involves copying the disk
8. No VMotion with physical mode RDMs

Virtual mode RDMs address some of these issues, allowing raw LUNs to be treated very much like virtual disks and enabling functionality like VMotion, snapshotting, and cloning. Virtual mode RDMs are acceptable in most cases where RDMs are required. For example, virtual mode RDMs can be used in virtual-to-virtual cluster across physical hosts. Note that physical-to-virtual clusters across boxes, though, require physical mode RDMs.

While virtual disks will work for the large majority of applications and workloads in a VI environment, the use of RDMs–either virtual mode RDMs or physical mode RDMs–can help eliminate potential compatibility issues or allow applications to run virtualized without any loss of functionality.

98. When users are logon to their Virtual Machines via View Client, when they wish to end the session, should they choose “disconnect” or “disconnect and log off” option ?
The first option is Disconnect. With Disconnect, the user remains logged on. Any programs that the user is running continue to run and no other users (except for an Administrator) can connect to this desktop. If an administrator chooses, they may log into the desktop, but will automatically log the user out and force any programs the user was running to end. The second option is Disconnect and Log off. This option allows the user to log off and it allows other users to access this desktop.

99. What is the purpose of the cache lifetime setting for the offline desktop ?
The data on each offline system is encrypted and has a cache lifetime controlled through policy, if the client loses contact with the View Connection Server, the cache lifetime is the period in which the user can continue to use the desktop before they are refused access; this countdown is reset once the connection is re-established.

100. Does Offline Desktop support tunneled or non tunneled communications ?
Offline Desktop supports tunneled or nonatunneled communications for LANabased data transfers. When tunneling is enabled, all traffic is routed through the View Connection Server.

Is VMware interview difficult?