Virtualization definitions beginning with D

A data center (sometimes spelled datacenter) is a centralized repository, either physical or virtual for the storage, management, and dissemination of data and information organized around a particular body of knowledge or pertaining to a particular business
Dell - Cite This Source - This Definition
Browse Related Terms: Autonomic Computing, Clustering, Grid Computing, I/O, infrastructure, on-demand computing, pervasive computing, ubiquitous computing, utility computing, virtual infrastructure, workload management

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A virtual hard disk that stores the changes to an associated parent virtual hard disk for the purpose of keeping the parent intact. The differencing disk is a separate .vhd file that is associated with the .vhd file of the parent disk. Changes continue to accumulate in the differencing disk until it is merged to the parent disk.
Microsoft - Cite This Source - This Definition
Browse Related Terms: compact, dynamically expanding virtual hard disk, fixed-size virtual hard disk, Growable Disk, physical disk, Preallocated Disk, SRAT (System Resource Allocation Table), Thrashing, virtual disk, virtual floppy disk

Also known as the Host or host operating system. dom0 refers to the host instance of Red Hat Enterprise Linux running the Hypervisor which facilitates virtualization of guest operating systems. Dom0 runs on and manages the physical hardware and resource allocation for itself and the guest operating systems.
Red Hat - Cite This Source - This Definition
Browse Related Terms: bare-metal, emulation, full virtualization, guest operating system, host OS (Operating System), hosted environment, Hosted Virtualization, operating system virtualization, partitioned, server virtualization, virtual machine, virtualization

A domain is the execution context that contains a running virtual machine. The relationship between virtual machines and domains on Xen is similar to that between programs and processes in an operating system: a virtual machine is a persistent entity that resides on disk (somewhat like a program). When it is loaded for execution, it runs in a domain. Each domain has a domain ID.
Xen.org - Cite This Source - This Definition
Browse Related Terms: domain 0, domain ID, domains, domu, exokernel, Host, MAC Addresses, microkernel, Xen

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The first domain to be started on a Xen machine. Domain 0 is responsible for managing the system.
Xen.org - Cite This Source - This Definition
Browse Related Terms: Domain, domain ID, domains, domu, exokernel, Host, MAC Addresses, microkernel, Xen

A unique identifier for a domain, analogous to a process ID in an operating system.
Xen.org - Cite This Source - This Definition
Browse Related Terms: Domain, domain 0, domains, domu, exokernel, Host, MAC Addresses, microkernel, Xen

domU and Domains are both domains. Domains run on the Hypervisor. The term domains has a similar meaning to Virtual machines and the two are technically interchangeable. A domain is a Virtual Machine.
Red Hat - Cite This Source - This Definition
Browse Related Terms: Domain, domain 0, domain ID, domu, exokernel, Host, MAC Addresses, microkernel, Xen

domU refers to the guest operating system which run on the host system (Domains).
Red Hat - Cite This Source - This Definition
Browse Related Terms: Domain, domain 0, domain ID, domains, exokernel, Host, MAC Addresses, microkernel, Xen

In virtual environments the setup of new systems and recovery of operating systems are much simpler than with standard recovery methods. There is no need to bother about adequate and special hardware, or to deal with patches and firmware. File recovery uses one single step for file encapsulation of virtual machines. This reduces the server to a set of files that can be restored on any hardware. Consequently, complete virtual machines can be replicated with replication software at a recovery location and the recovery time is reduced to a few hours.
Stonesoft - Cite This Source - This Definition
ensuring the availability of business services at a remote relocation in the event that the infrastructure becomes completely unavailable at the primary location.
Versatile Systems - Cite This Source - This Definition
Browse Related Terms: business continuity, capacity planning, five nines, HA (High Availability), policy-based automation, Provisioning, SLA (Service Level Agreement), TCO (Total Cost of Ownership), Virtual Machine Management Service

A virtual hard disk that grows in size each time it is modified. This type of virtual hard disk starts as a 3 KB .vhd file and can grow as large as the maximum size specified when the file was created. The only way to reduce the file size is to zero out the deleted data and then compact the virtual hard disk.
Microsoft - Cite This Source - This Definition
Browse Related Terms: compact, differencing virtual hard disk, fixed-size virtual hard disk, Growable Disk, physical disk, Preallocated Disk, SRAT (System Resource Allocation Table), Thrashing, virtual disk, virtual floppy disk

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