Lingo, jargon, acronyms...we've tried to define them here. Also, when you see a green asterisk 
next to a term, hover over it with your mouse pointer to reveal its definition.
Business Continuity
The ability of an organization to continue to function even after a disastrous event, accomplished through the deployment of redundant hardware and software, the use of fault tolerant systems, as well as a solid backup and recovery strategy.
CapEx
Capital expenditures, or capital expense, refers to the cost of acquiring assets with a relative long useful life (over a stated cost threshold) which will be depreciated over time. Capital budgets are administered separately from operating budgets.
Cloning
Copies of a virtual machine, created in a single installation and configuration process. Simplifies and accelerates the distribution of standardized computing environments to employees or the creation of a base configuration for testing.
Cluster
Originally a group of disk sectors, the meaning has expanded to include a group of virtual servers linked to provide greater utilization than possible by standalone servers.
Guest OS
An operating system installed on a virtual server.
Headroom
The un-utilized capacity on a physical server, which varies according to the demands placed on the machine, including number of virtual machines, applications, and clients.
Host OS
The base operating system installed on a physical machine, on top of which the guest operating systems are installed in virtual machines, and which interacts with the hardware.
Hypervisor
The virtualization software layer managing hardware requests from a guest OS, simulating answers from a real hardware. A program that allows running several virtual machines, potentially running several different operating systems. It controls the CPU as well as all hardware resources, providing every operating system with the required resources.
I/O blender
The conflicts caused by input/output (I/O) traffic associated with multiple virtual machines co-located on a single hardware unit, resulting in performance delays and failures.
OpEx
Operating expenditures, or operating expense, refers to the costs incurred by an organization which will be recognized within the current period.
OS image
An exact replica of the operating system from one device, stored on a second device.
Physical server
A hardware-based computer, as opposed to a software-based virtual machine.
Provisioning
The process of establishing appropriate linkages between systems, applications, and databases. Access rights are defined, and resources identified in accordance with system security and stability requirements.
Quality of Service
- also SLA (Service Level Agreement): An agreement between a service provider (whether a corporate function or external vendor) and a customer (again, internal or external) regulating offered service in several aspects, from amount of resources available to time availability, to recovery timeframe.
Snapshot
- also Virtual Machine Snapshot: A file-based capture of the state, disk data, and configuration of a virtual machine at a specific point in time. Conserves the state of a virtual machine so it can be moved back at any future time to an earlier, stable system state.
Storage arrays
A series of storage devices linked in such a way as to distribute the storage function more efficiently.
Storage management applications
Software which regulates the movement / placement / retrieval of data.
Virtual data center
A series of virtual servers linked together, based on the premise that interactions between virtual servers on the same physical server are faster and more efficient than interactions between separate physical devices.
Virtual Machine (VM)
A computer within a computer, implemented in software. A virtual machine emulates a complete hardware system, from processor to network card, in a self-contained, isolated software environment, enabling the simultaneous operation of otherwise incompatible operating systems.
Virtual server
A physical server which contains multiple virtual machines.
VM sprawl
The proliferation of multiple computers inside a company infrastructure.
