Virtualization is the abstraction of physical elements and location. IT resources – servers, applications, desktops, storage, and networking – are uncoupled from physical devices and presented as logical resources. Virtualization technologies create and perform mapping between physical and logical.
Who uses virtualization, and why?
Virtualization is used widely in small to large data centers by corporations, government entities, service providers, and ISVs, as well as within SMB IT environments.
Fundamental to cloud computing, virtualization enables IT organizations to pool and share resources across multiple users and deploy quickly without over provisioning. More efficient resource utilization results in lower equipment, space, and power and cooling costs. Virtualization also helps reduce complexity and management overhead, increase application availability, disaster recovery, and increase IT security.
How this technology works
Virtualization in IT environments encompasses several forms including:
Server virtualization utilizes a thin software layer called a hypervisor to create “virtual machines” (VMs), an isolated software container with an operating system and application inside. The VM is called a guest machine and is completely independent, allowing many to run simultaneously on a single physical “host” machine. The hypervisor allocates host resources (CPU, memory) dynamically to each VM as needed.
Storage virtualization has many forms, spanning block, file, disk and tape. Physical storage is hidden and presented as logical volumes, including different mediums (e.g. tape as disk). Storage virtualization enables pooling devices and provisioning capacity to users as logical drives. Advanced solutions enable arrays to be managed as one logical unit and capacity provisioned from one logical pool.
Thin provisioning allocates shared physical resources (memory, CPU, disk) based on need versus the amount appearing available. This allows more resources to be allocated than physically available – called oversubscription – and avoids resources being left unused.
Network virtualization enables network resources (hardware and software) to be deployed and managed as logical vs. physical elements. Multiple physical networks can be consolidated into a single logical network, or a single physical network can be segmented into separate logical networks. Network virtualization also includes software emulating switching functionality between virtual machines.
Virtual Desktop Infrastructure (VDI) decouples the desktop from the physical machine. In a VDI environment, the desktop O/S and applications reside inside a virtual machine running on a host computer, with data residing on shared storage. Users access their virtual desktop from any computer or mobile device over a private network or internet connection.
Benefits of virtualization
IT virtualization provides numerous benefits, to include: