VSphere Components

• VMWare ESX/ESXi
• VMWare VCenter Server
• VMware VSphere Client
• VMWare VSphere Web access
• VMWare vStorage VMFS
• VMWare Virtual SMP.

Why Use virtual Machines ?

Physical Machines :
           > Difficult to move or copy
           > Bound to a specific set of hardware components
           > Often has short life cycle
           > Requires personal contact to upgrade hardware
Virtual Machines :
          > Easy to move and copy
                * Encapsulate into files
                * Independent of physical hardware
          > Easy to manage
                * Isolated from other virtual machines running on the same physical hardware
                * Insulated from physical hardware changes

What is Virtual Machine

From user's perspective, it is a software platform that,like a physical computer,runs an operating system and applications.
from the hypervisor's perspective, it is a discrete set of file.these are the main file :
                 > Configuration Files
                 > Virtual harddisk files
                 > NVRAM Settings file
                 > Log file

What is Virtualization

*  Virtualization is technology that transforms hardware into software.
*  Virtualization allows you to run multiple Operating Systems as virtual Machines on a single computer
*  Each copy of an operating system is installed into a virtual machine.
*  Virtualization is not simulation and emulation

Teaming,Cloning,Snapshot and Record-Play

Teaming :

• Group of Virtual Machines start & Stop at a time.
• Teaming available only in the workstation.
• The extension of teaming configuration file is .vmtm
• When we start the team then it tackes some delay between the vms this delay is called as delay time.
• By default delay time is 10sec.

Cloning :

• Creating same image
• there are 2 types of clones 1) Linked Clone 2 ) Full Clone
• Linked clone is nothing but it won't copy the original files but it creates a linked file. 
• the disadvantage is If we remove the original VM then the second VM is won't work.
• the advantage with the linked clone is it occupies less space and time.

VM Files and Extesions

1 ) .vmdk (Dot vmdk) - vm harddisk files,guest os,softwares
2 ) .vmx  (dot vmx) - vm configuration files such as vmware,location,memory,hard disk information
3 ) .log (dot log) - Log Files
4 ) .vmsd (dot vmsd) - Snapshot descriptions
5 ) .nvram (dot nvram) - non volatile RAM
6 ) .vmtm (dot vmtm)- Teaming Extension.

FAQ's

 1) How many iSCSI targets will ESX support 8 for 3.01
 Ans: 64 for 3.5
2) What is Vmotion
 Ans: Ability to move running vm from one host to another3) What is the Maximum Host Failure allowed in a cluster
 Ans: 4