Users Guide

42 Storage Solutions Guide
Appendix C: Glossary
BFI — Booting a system from a LUN residing on a iSCSI storage array
GUEST OS — The operating system that is running within a virtual machine.
HYPER-V MANAGER — The Microsoft Management Console (MMC) that
manages the Hyper-V Virtualization Role on Windows Server 2008.
HYPERVISOR — A layer of software that sits just above the hardware and below
the parent partition and VMs. Its primary job is to provide isolated execution
environments called partitions. Each partition has its own set of hardware
resources (CPU, memory, and devices).
LUN (LOGICAL UNIT NUMBER)—In this solutions guide, a LUN refers to a
unique disk that is provisioned to a server from a storage enclosure or array.
For the MD3000 and MD3000i, the documentation and user interface refer
to a LUN as a virtual disk.
MPIO — Multi-Path IO provides fault-tolerance and performance
enhancements by implementing more than one physical connection path
from servers to storage.
PARENT PARTITION — A partition that is created first and owns all the
resources that the hypervisor does not own including most devices and system
memory. It hosts the virtualization stack, and creates and manages the child
partitions.
PASSTHROUGH DISK — Disks that are mapped directly to VMs and provide
raw access to the underlying physical disk.
STORAGE ARRAY — A collection of disks external to the server that support an
advanced feature set including RAID and memory caching. For Dell, this
category includes iSCSI, fibre channel, and SAS storage arrays.
STORAGE ENCLOSURE — A collection of disks external to the server contained
within a single enclosure. The enclosure does not contain an internal RAID
controller. Commonly referred to as a JBOD.
VHD — Virtual Hard Disk. Mimics the capabilities of a physical disk for a VM
and encapsulates logical blocks within a single file.
VM — A Hyper-V Virtual Machine.
VM FILES — The virtual machine configuration, device state, and memory
(XML, VSV, and BIN) files.