Virtualization Terminology
The following terms are defined in the context of Virtualization Manager.
Note:
The usage of VM refers to a Virtual Machine, not Virtualization Manager.
Table: Virtualization Terminology
Column name | Description |
|---|---|
|
Capacity: Datastore |
The capacity of all the datastores hosting a Virtual Machine File System (VMFS) or, for NAS storage, a Network File System (NFS). |
|
Capacity: Logical |
Also known as the Virtual Disks or Volume, this is the capacity of the virtual machine, derived from the virtual machine's VMDK file(s). |
|
Datastore |
The datastore is the container for the VMs and their configuration files, and other files, such as the ISO files that are used for installing a virtual machine. A datastore provides the virtual storage resources via mapping to physical storage on DAS SCSI, FC SAN arrays, iSCSI, or NAS drives. The datastore is the storage provisioning source for one or more VMs on one or more hosts. |
|
VM Server |
The physical server (bare metal box) that is hosting the VMs via the virtualization software, such as ESX. Virtual machines reside on a VM Server, sometimes referred to as a Virtual Host or Virtual Machine Server. |
|
Physical (Raw) Disk |
A VM can use either a virtual disk or it can access the host machine's physical disk drive: Raw Device Mapping or Raw Disk Map (RDM) file. Raw disk mapping to a LUN may have been chosen in order to optimize performance. |
|
Virtual Disks |
Also known as a Virtual Hard Drive or Virtual Machine Images (.VMDK file), this is the storage that is available to a guest operating system. It appears as a physical disk to the guest operating system, but it actually is a file that encapsulates the OS, applications, and data files of the VM. The VMDK file is accessed as if it were a physical hard disk. VMDK files can be either on the host or stored remotely. |
|
VM Guest |
Also known as a VM Instance; the logical server running on a VM Server. Note: All host names within a domain must be unique, especially when VM cloning occurs. |
|
Virtual Host |
The physical server (bare metal box) that is hosting the VMs via the virtualization software, such as ESX. Virtual machines reside on a VM Server, sometimes referred to as a Virtual Host or Virtual Machine Server. |
|
Virtual Machine (VM) |
The container for the guest operating system and applications; each VM is separate from all other VMs, even though they may share physical resources, such as memory and storage devices. |
|
VM Server |
VM Server is used throughout the reports to represent the physical server that is hosting the Virtual Machines; for example, the physical server running ESX. |
|
VMDK |
Note that for Raw Mapping (RDM), the VMDK file simply contains the metadata to map to a LUN. |
|
VMFS |
The Virtual Machine File System, with a hierarchical directory, provides the structure for managing access to shared, clustered storage. Each VM has a single subdirectory in the VMFS volume for the VMDK files (virtual disks). For raw disk mapping, the VMFS is mounted on the Virtual Machine. |
|
Volume |
The Volume is the storage that is exposed to the OS (filesystems mounted it on it). A Volume maps to logical disks, such as C:\ and D:\, as seen by the guest OS. These logical disks can be:
Note: Volume Usage shown in IT Analytics represents logical disk usage. |