The VMware Technical Publications Glossary defines terms as used in VMware® technical documentation.
In ESX Server 2.x, a disk mode in which software running in the virtual machine appears to write changes to the disk. Changes are stored in a temporary .REDO file. If a system administrator deletes the redo-log file, the virtual machine returns to the state it was in the last time it was used in persistent mode. See also disk mode.
(n.) A duplicate of a virtual machine. (v.) To make a copy of a virtual machine. When a clone is created, vCenter Server provides an option for customizing the guest operating system of that virtual machine. Hosted products distinguish between full clones and linked clones. See also full clone, linked clone.
An extended compute resource that represents a cluster of hosts available for backing virtual machines. See also compute resource.
A managed object that represents either a single host or a cluster of hosts available for backing virtual machines. See also cluster compute resource.
A virtual machine of the latest version supported by the product in use. See also legacy virtual machine.
In hosted products, any type of network connection between virtual machines and the host that does not use the default bridged, host-only, or network address translation (NAT) configurations. For instance, different virtual machines can be connected to the host by separate networks or connected to each other and not to the host. Any network topology is possible.
A property of a virtual disk that defines its external behavior (how the virtualization layer treats its data. It is invisible to the guest operating system. Available modes vary by product. See also persistent mode, nonpersistent mode and append mode.
A physical switch that manages network traffic between machines. A switch has multiple ports, each of which can be connected to a machine or to another switch on the network. See also virtual switch.
An action that is of interest to vCenter Server. Each event triggers an event message. Event messages are archived in the vCenter Server database. Messages appear in two locations in the user interface: the Events option in the navigation bar and the Events tab for objects under the Inventory button.
A Fibre Channel network topology in which devices pass data to each other through interconnecting switches. A fabric is used in many SANs. Fabrics are typically divided into zones. Also called switched fabric or Fibre Channel fabric. See also FC (Fibre Channel).
A managed entity used to group other managed entities. Folder types are determined by the types of child entities they contain. See also child.
A complete copy of the original virtual machine, including all associated virtual disks. See also linked clone.
A display mode in which the virtual machine’s display fills the entire screen. (The user has no access to the VMware Workstation user interface.) The user cannot create, reconfigure, or start virtual machines. A system administrator performs those functions. See also quick switch mode.
A set of users assigned a common set of privileges. A group may contain other groups. See also service console.
An operating system that runs inside a virtual machine. See also host operating system.
In ESX server software, one of two modes for licensing VMware software. License files reside on the host. Feature availability is tied strictly to the host in which the file resides. See also server-based licensing.
VMware products (including Workstation, VMware Player, VMware Server, VMware ACE, and Lab Manager) that run as applications on physical machines with operating systems such as Microsoft Windows or Linux. See also hypervisor.
In hosted products, a type of network connection between a virtual machine and the host. With host-only networking, a virtual machine is connected to the host on a private network, which normally is not visible outside the host. Multiple virtual machines configured with host-only networking on the same host are on the same network. See also NAT (network address translation).
An operating system that runs on the host machine. See also guest operating system.
A type of virtual disk that is not affected by snapshots. You can configure independent disks in persistent and nonpersistent modes. See also nonpersistent mode, persistent mode.
Storage virtualization devices are those that aggregate capacity from multiple heterogeneous arrays and manage a logical representation of this capacity. Models that belong to this group are array-based controllers only and not server-based or switch-based controllers. Most of these devices can also have physical disks installed internally that are presented to hosts as physical SAN LUNs, which are not virtualized. When these devices are supported in the internal storage configuration, this refers to the LUNs presented from disks internal to the array and not those virtualized from other arrays which they aggregate.
A private virtual network that is available only to virtual machines within the same team. See also team, virtual network.
The method used for licensing VMware software. A license file can be located on an ESX server host or on a license server. vCenter Server uses server-based licensing. ESX server licensing can be server-based or host-based at the option of the system administrator. See also host-based licensing, server-based licensing.
A copy of the original virtual machine. The copy must have access to the parent virtual machine’s virtual disks. The linked clone stores changes to the virtual disks in a separate set of files. See also full clone.
A managed object that is present in the inventory. See also inventory, managed object.
The process of moving a virtual machine between hosts. Unless VMotion or Storage VMotion is used, the virtual machine must be powered off when you migrate it. See also migration with VMotion.
In hosted networking, a type of network connection that enables you to connect your virtual machines to an external network when you have only one IP network address and the host computer uses that address. The VMware NAT device passes network data between one or more virtual machines and the external network. It identifies incoming data packets intended for each virtual machine and sends them to the correct destination. See also host-only networking.
A diagnostic command that helps determine how a system name or IP address is resolved. Because it can display current connections using NetBIOS over TCP/IP, nbtstat is useful for determining whether Windows systems are online from a NetBIOS view. See also NetBIOS (network basic input/output system).
A disk mode in which all disk writes issued by software running inside a virtual machine appear to be written to the independent disk. In fact, they are discarded after the virtual machine is powered off. As a result, a virtual disk or physical disk in independent-nonpersistent mode is not modified by activity in the virtual machine. See also disk mode, persistent mode.
A distribution format for virtual appliances that uses existing packaging tools to combine one or more virtual machines with a standards-based XML wrapper. OVF gives the virtualization platform a portable package containing all required installation and configuration parameters for virtual machines. This format allows any virtualization platform that implements the standard to correctly install and run virtual machines.
A component of an operating system that provides virtual memory for the system. Recently used pages of memory are swapped out to this area on the disk to make room in physical memory (RAM) for newer memory pages. Also called a “swap file.” See also virtual memory.
Free virtual machines that are intended to demonstrate the Virtual Machine Interface (VMI) for virtual machine hypervisors. See also hypervisor.
(1) The source virtual machine from which you take a snapshot or make a clone. If you delete the parent virtual machine, any snapshot becomes permanently disabled. (2) In a VMware vSphere inventory, the managed entity that immediately encloses a given entity (considered the child entity). See also full clone, linked clone, snapshot, template.
A disk mode in which all disk writes issued by software running inside a virtual machine are immediately and permanently written to a virtual disk that is configured as an independent disk. As a result, a virtual disk or physical disk in independent-persistent mode behaves like a conventional disk drive on a physical computer. See also disk mode, nonpersistent mode.
In hosted products, a hard disk in a virtual machine that is mapped to a physical disk drive or partition on the host machine. A virtual machine’s disk can be stored as a file on the host file system or on a local hard disk. When a virtual machine is configured to use a physical disk, vCenter Server directly accesses the local disk or partition as a raw device (not as a file on a file system). See also virtual disk.
A network of physical machines (plus cabling, switches, routers, and so on) that are connected so that they can send data to and receive data from each other. See also virtual network.
A construct for configuring virtual network options such as bandwidth limitations and VLAN tagging policies for each member port. Virtual networks that are connected to the same port group, share network policy configuration. See also virtual network, VLAN (virtual local area network).
A display mode in which the virtual machine’s display fills most of the screen. In this mode, tabs at the top of the screen enable you to switch quickly from one running virtual machine to another. See also full screen switch mode.
The file that stores changes made to a disk in all modes except the persistent and independent-persistent modes. For a disk in nonpersistent mode, the redo-log file is deleted when you power off or reset the virtual machine without writing any changes to the disk. You can permanently apply the changes saved in the redo-log file to a disk in undoable mode so that they become part of the main disk files. See also disk mode.
To return a virtual machine to operation from its suspended state. When you resume a suspended virtual machine, all applications are in the same state as when the virtual machine was suspended. See also suspend.
To restore the status of the active virtual machine to its immediate parent snapshot. This parent is represented in the Snapshot manager by the snapshot appearing to the left of the You are here icon. See also Go to snapshot, Snapshot Manager, You are here icon.
A mode of licensing VMware software in which all license keys are administered by a license server, which manages a central license pool. Feature entitlement is checked out and returned on demand. See also host-based licensing.
The command-line interface for an ESX server system that enables administrators to configure the system. The service console is installed as the first component and used to bootstrap the ESX server installation and configuration. The service console also boots the system and initiates execution of the virtualization layer and resource manager. You can open the service console directly on an ESX server system. If the ESX server system’s configuration allows Telnet or SSH connections, you can also connect remotely to the service console.
A folder on a host computer—or on a network drive accessible from the host computer—that can be used by both the host computer and one or more virtual machines. It provides a simple way of sharing files between host and guest or among virtual machines. In a Windows virtual machine, shared folders appear in My Network Places (Network Neighborhood in a Windows NT virtual machine) under VMware Shared Folders. In a Linux virtual machine, shared folders appear under a specified mount point.
To reclaim unused space in a virtual disk. If a disk has empty space, shrinking reduces the amount of space the virtual disk occupies on the host drive. Shrinking virtual disks is a way to update an older virtual disk to the format supported by the current version of vCenter Server. You cannot shrink preallocated virtual disks or physical disks.
A unit of CPU and memory that can accommodate the CPU and memory reservation requirements of the largest virtual machine in your cluster. Spare capacity for failover is maintained on hosts in the cluster in slot sizes, so that any virtual machine in the cluster can fit in the slot size and be able to be failed over. Represents potential computing capacity on a node. A virtual machine can run in an empty slot in the event of failover.
Technical definition: A unit of CPU and memory that can accommodate the CPU and memory reservation requirements of the largest virtual machine in the cluster. Spare capacity for failover is maintained on hosts in the cluster in slot sizes, so that any virtual machine in the cluster can fit in the slot size and be able to be failed over.
A reproduction of the virtual machine just as it was when you took the snapshot, including the state of the data on all the virtual machine’s disks and the virtual machine’s power state (on, off, or suspended). You can take a snapshot when a virtual machine is powered on, powered off, or suspended. See also independent disk.
A control that enables you to take actions on any of the snapshots associated with the selected virtual machine. See also snapshot.
A state in which settings are preserved and actions are no longer performed. To turn off a virtual machine while preserving the current state of a running virtual machine. See also resume.
A reliable transfer protocol used between two endpoints on a network. TCP is built on top of the Internet Protocol (IP). See also TCP/IP (Transmission Control Protocol/Internet Protocol).
The set of protocols that is the language of the Internet, designed to enable communication between networks regardless of the computing technologies that they use. TCP connects hosts and provides a reliable exchange of data streams with guaranteed delivery. IP specifies the format of packets and handles addressing. See also UDP (User Datagram Protocol).
A group of virtual machines configured to operate as one object. You can power on, power off, and suspend a team with one command. You can configure a team to communicate independently of any other virtual or real network by setting up a LAN segment. See also LAN segment, NIC teaming, virtual network.
A master image of a virtual machine. The template typically includes a specified operating system and a configuration that provides virtual counterparts to hardware components. Optionally, a template can include an installed guest operating system and a set of applications. Templates are used by vCenter Server to create new virtual machines. See also linked clone, parent, snapshot.
One of the core protocols in the Internet protocol suite. UDP enables a program to send packets (datagrams) to other programs on remote machines. UDP does not require a connection and does not guarantee reliable communication. It is a quick and efficient method for broadcasting messages over a network. See also TCP/IP (Transmission Control Protocol/Internet Protocol).
A number used to uniquely identify some object or entity. The UUID is either assigned by VMware vSphere (in the case of virtual machines) or is hardware-assigned (in the case of SCSI LUNs). vCenter Server attempts to ensure that the UUIDs of all virtual machines being managed are unique, changing the UUIDs of conflicting virtual machines if necessary.
(1) An XML document that contains information about objects, particularly virtual machines and hosts. Use a view to access virtual machines and other top-level objects through the Web service. (2) In the Perl Toolkit, an object stored in the client that encapsulates the properties of a managed object with methods to access the properties and act on the managed object.
A software solution that is composed of one or more virtual machines. A virtual appliance is packaged as a unit by an appliance vendor and is deployed, managed, and maintained as a unit. Converting virtual appliances allows you to add preconfigured virtual machines to your Virtual Center, ESX Server, Workstation, or Player inventory.
A file or set of files that appears as a physical disk drive to a guest operating system. These files can be on the host machine or on a remote file system. See also growable disk, physical disk.
The devices that make up a virtual machine. The virtual hardware includes the virtual disk, removable devices such as the DVD-ROM/CD-ROM and floppy drives, and the virtual Ethernet adapter. See also virtual machine settings editor.
The specification of which virtual devices, such as disks and memory, are present in a virtual machine and how they are mapped to host files and devices. In vConverter, VMware virtual machines whose disks have been populated by restoring from a backup or by some other direct means of copying undergo configuration to enable them to boot in VMware products. See also virtual machine.
An extension of a system’s physical memory, enabled by the declaration of a page file. See also page file.
A network connecting virtual machines that does not depend on physical hardware connections. For example, you can create a virtual network between a virtual machine and a host that has no external network connections. You can also create a LAN segment for communication between virtual machines on a team. See also LAN segment, team.
A component installed with VMware Tools that executes commands in the virtual machine, gracefully shuts down and resets the virtual machine, sends a heartbeat to VMware Migration Server, synchronizes the time of the guest operating system with the host operating system, and passes strings from the host operating system to the guest operating system.
An interface that provides access to one or more virtual machines on the local host or on a remote host running vCenter Server. You can view a virtual machine’s display to run programs within it, or you can modify guest operating system settings. You can also change the virtual machine’s configuration, install the guest operating system, or run the virtual machine in full screen mode.
A virtual network interface card that is configured on top of a system's physical Network adapter. See also NIC (network interface card).
An icon in the Snapshot manager that indicates the current status of the active virtual machine. Checking the position of this icon can help you decide whether to revert to a snapshot or go to a snapshot. See also Go to snapshot, revert to snapshot, Snapshot Manager.