Introductin to virtualization i
- 2. Introduction to virtualization - I • At the end of this session, we will be able to understand:- • What is virtualization ? • Need of virtualization
- 3. What is virtualization • Virtualization is the creation of a virtual version of something, that includes hardware, OS, storage, application, network. • The main goal of virtualization is centralize administration & Scalability.
- 4. • Virtualization allows multiple operating system to run simultaneously on a single computer by distributing hardware to each operating system. • Each instance is known as Virtual Machine or guest OS. Each “guest” OS is managed by a Virtual Machine Monitor (VMM), also known as a hypervisor. Hardware Hypervisor VM 1 VM 2
- 5. Why do we need virtualization ? • Consolidation • Redundancy • Segregation • Legacy Hardware • Migration
- 6. Consolidation • It's common practice to dedicate each server to a single application. If several applications only use a small amount of processing power, the administrator can combine several machines into one server running multiple virtual environments. For companies that have hundreds or thousands of servers, the need for physical space can decrease significantly. This saves on: • Cost : 10000$ per maintenance cost per machine • Space: Less servers, less space needed • Energy: Savings by up to 80% • Environment: Reduced CO2 emissions due to decrease in number of servers
- 7. Redundancy • Server virtualization provides a way for companies to practice redundancy without purchasing additional hardware. Redundancy refers to running the same application on multiple servers. It's a safety measure -- if a server fails for any reason, another server running the same Application can take its place. • This minimizes any interruption in service. It wouldn't make sense to build two virtual servers performing the same application on the same physical server. If the physical server were to crash, both virtual servers would also fail. In most cases, administrators will create redundant virtual servers on different physical machines.
- 8. Segregation • Virtual servers offer programmers isolated, independent systems in which they can test new applications or operating systems. Rather than buying a dedicated physical machine, the network administrator can create a virtual server on an existing machine. • Because each virtual server is independent in relation to all the other servers, programmers can run software without worrying about affecting other applications.
- 9. Legacy hardware • Server hardware will eventually become obsolete, and switching from one system to another can be difficult. In order to continue offering the services provided by these outdated systems – sometimes called legacy systems -- a network administrator could create a virtual version of the hardware on modern servers. From an application perspective, nothing has changed. • The programs perform as if they were still running on the old hardware. This can give the company time to transition to new processes without worrying about hardware failures, particularly if the company that produced the legacy hardware no longer exists and can't fix broken equipment.
- 10. Migration • An emerging trend in server virtualization is called migration. • Migration refers to moving a server environment from one place to another. • With the right hardware and software, it's possible to move a virtual server from one physical machine in a network to another. • Originally, this was possible only if both physical machines ran on the same hardware, operating system and processor. • It's possible now to migrate virtual servers from one physical machine to another even if both machines have different processors, but only if the processors come from the same manufacturer.