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Glossary

8B/10B encoding
An algorithm for encoding data for transmission in which each eight-bit data byte is converted to a 10-bit transmission character. Invented and patented by IBM Corporation, 8B/10B encoding is used in transmitting data on Infiniband, Fibre Channel, ESCON and Gigabit Ethernet. 8B/10B encoding supports continuous transmission with a balanced number of ones and zeroes in the code stream and detects single bit transmission errors.

BMC A Baseboard Management Controller is a fairly low-cost controller used on some servers; it can generate various alerts and allow for system restarts when the operating system is hung.

CapEx Capital expenditures are expenses associated with the purchase or upgrade of equipment (physical assets).

Copy on write
A technique for maintaining a point in time copy of a collection of data by copying only data which is modified after the instant of replicate initiation. The original source data is used to satisfy read request for both the source data itself and for the unmodified portion of the point in time copy.

Guest Operating System (GOS) The Systems installed and running inside of a virtual machine.
HA - High availability is the ability of redundant components to fail over the other if one should stop working

Host Bus Adapter (HBA) A Hardware adapter card that connects the host to a device, e.g., a SCSI disk, an array of SCSI disks, or a storage area network using Fibre Channel or iSCSI technologies.

Host Channel Adapter (HCA) is the adapter/interface between a computer and an InfiniBand network

Host Operating System The operating system installed on the physical server that is running the virtualization software.

HPCC High-performance computing clusters are used for HPC applications that are cluster-aware-, that is, they can distribute the application workload across a number of systems or processors to get the work done more quickly and efficiently than on a single system/processor. In addition to the attributes of HPC, HPCC requires inter processor communications (IPC) capability across high-speed interconnect such as 10GbE, InfiniBand, or Myrinet

Hypervisor (also, virtual machine monitor) A thin , guest-OS-independent virtualization layer that is loaded onto bare metal, which interacts with the hardware directly and creates virtual machines in which operating systems, either enlightened or not, can run. The hypervisor virtualizes hardware resources, such as memory and CPUs, for the different virtual machines (VMs) and their guest operating systems.

InfiniBand A scalable, high speed, switched fabric network, often used in HPCC due to its high bandwidth. InfiniBand (IB) switch modules are available for a number of blade systems. Servers connect to an IB network through a host channel adapter (HCA).

IPoIB Internet Protocol over InfiniBand is IP packets encapsulated in the InfiniBand data link layer, allowing computers on an IB networks to communicate to IP devices.

IPMI- The Intelligent Platform Management Interface is a set of specifications created by a consortium of platform vendors which provides a set of low-level protocols and data records used to provide out-of -band manageability and access to hardware-management information via a set of in-band application programming interfaces.

LDAP Lightweight Directory Access Protocol is an application protocol for querying and modifying directory services running over TCP/IP.

Longhorn- Code name used by Microsoft for the major releases of Windows Server scheduled for 2007. Includes the base code for the Windows virtualization hypervisor, code-named Viridian (aka Windows Server Virtualization), which is a scheduled for within 180 days of Longhorn’s GA release.

Logical Unit Number (LUN)- An address of a disk or storage device. The term is used to describe SCSI disk identifiers as well as logical volumes in storage networks.

LUN masking- Done by host bus adapters in cooperation with software in the server, LUN masking works by restricting the logical unit numbers (LUNs) for which operating system commands are accepted.

Microsoft Virtual Server- A Virtualization Platform that runs as an application on top of Windows XP Professional and the Windows Server 2003 Family. Microsoft Virtual Server is very similar to VMware GSX Server in the way it leverages a host platform. See GSX Server.

Multi-pathing software- Server-resident software that manages a server's use of multiple paths to a storage device. Typically this is implemented to improve resilience and protect against failure in the storage network.

NAS- Network attached storage allows systems to access and share files ver an IP network using the CIFS protocol for Microsoft Windows and NFS for UNIX and Linux protocols. NAS devises contain disks (usually RAID disks), and a very thin server that specializes in maintaining files systems intelligence and fast access to data at the file level.

NFS- Network File System is a UDP- or TCP/IP-based protocol for accessing files on a remoter system (or NAS storage device) as if they were local files. Most often used with UNIX or Linux.

NIC- A network interface card is the component that connects a server to a network. Typically, blade servers come standard with redundant 1Gb Ethernet NICs. These can be upgraded to 10GbE and can have a TCP Offload Engine (TOE) option for improving the speed of communication with high-speed LANs or iSCSI SANs.

N_Port ID Virtualization or NPIV is a Fibre Channel facility allowing multiple N_Port IDs to share a single single physical N_Port. This allows multiple Fibre Channel initiators to occupy a single physical port, easing hardware requirements in Storage area network design, especially where virtual SANs are called for. NPIV is defined by the Technical Committee T11.

OpEx Operating Expenses are expenses incurred for ongoing operations and maintenance, excluding capital expenses (CapEx). This includes salaries, ongoing facilities costs such as power and cooling, and equipment maintenance.

Out-of-band infrastructure (OOBI) management- Allow a remote management sysytem to monitor and control all components of a system without requiring the use of the host operating systems and regardless of the currant power state of the system

Paravirtualization- Virtualization approach in which the guest operating systems are modified to know they are running in a virtual environment and interface with a special API to communicate with the virtualization layer, allowing performance to be significantly improved. The performance benefits, however, must be weighted against the need to modify the guest operating system.

PXE- Preboot Execution Environment boot allows a server to boot over a network (as long as your’re using DHCP), allowing servers to be diskless and retrieve their boot image from the network. Created as part of a bigger initiative from Intel called Wired for Management (WfM), which was introduced in 1998 to improve the manageability of desktop, mobile, and server systems.

QOS- Quality of Service For the 3Leaf V-8000, a mechanism to specify the minimum and maximum bandwidth that is allocated to either a VHBA or a VNIC.

Scale-out- Server architecture in which more servers are added to a group of servers sharing a workload, for example in a webserver farm or through a cluster.

Scale-up- Server architecture in which more compute power is added within a server to handle more workload

SOAP- SOAP (originally Simple Object Access Protocol lately also Service Oriented Architecture Protocol) is a protocol for exchanging XML-based messages over computer networks, normally using HTTP. SOAP forms the foundation layer of the Web services stack, providing a basic messaging framework that more abstract layers can build on.

TCO- Total cost of ownership is a financial measurement which includes hard and soft costs over a period of time (typically three years) and is used to evaluate purchase decisions, including not only purchase cost (capEx) but also ongoing costs (OpEx).

Viridian- Code name used by Microsoft for the Windows virtualization hypervisor, code-named Viridian (aka Windows Server Virtualization), which is scheduled for release within 180 days of Longhorn Server’s general availability (GA) release.

Virtual Dedicated Server- Another term for virtual private server, the virtual dedicated server allows users to have a dedicated server, despite the fact that their virtual server is on the same machine as other virtual dedicated servers.

Virtual Disk- An abstraction of a physical disk or logical storage device known to a 3Leaf V-8000 that gets exported to a compute node after it’s created.

Virtual HBA- A logical version of its physical counterpart, the VHBA is a software abstraction of a physical HBA on a 3Leaf V-8000 that gets exported to a compute node after it’s created.

Virtualization- The term virtualization refers to the abstraction of a computer’s physical resources so that it ‘hides’ physical characteristics from the applications, software and end users who interact with the machine.

Virtual Machine- It is a self-contained operating environment that behaves as if it is a separate computer. A virtual machine emulated a complete hardware system, including the processor, network adapter, removable drives, peripherals, and other devices. Multiple virtual machines configured with different guest operating system are capable of operating on the same host server simultaneously.

Virtual NIC- A logical version of its physical counterpart, the VNIC is a software abstraction of a physical NIC on a 3Leaf V-8000 that gets exported to a compute node after it’s created.
Virtual Private Server – A virtual private server means that the virtual server shares the same physical box as other virtual servers, but runs an individual operating system and allows its users priority access.

Virtual Server- A virtual server is a server run through virtualization, meaning it exists on the same physical machine as other virtual servers. The 3Leaf Systems V-8000 Virtual I/O Server provides a virtualization layer and aggregates network and storage resources.

Vmware ESX Server - Vmware’s flagship virtualization product, ESX Server is datacenter-class server virtualization software used for consolidating and partitioning servers in high performance environments. Installed on top of bare metal rather than being installed on top of another operating system, ESX gains performance increases through its highly efficient hypervisor/kernel. ESX Server is also capable of virtual SMP.

Vmware GSX Server- VMware’s GSX Server product is enterprise-class virtualization software that needs to be installed on top of either Linux or Windows.

Xen- Open source virtual machine monitor, it is software that runs on a host operating system and allows one to run several guest operating systems on top of the host on the same computer hardware at the same time. Modified versions of Linux and NetBSD can be used as hosts.

Zoning- Done by the fabric in a Fibre Channel SAN, zoning has a similar effect to that of HBA-based LUN masking. A tape drive’s port address is added to the fabric zone that contains the server that will control the backup operation and the online storage device that is the source for the data to be copied. If zones in the SAN of which other servers are part are configured so that the tape drive is not a part of the, those servers will experience no response to messages sent to the tape drive’s port address.

Glossary sources:
3Leaf Systems V-8000 Administrator’s Guide
Advanced Server Virtualization (Marshall, Reynolds, McCrory)
Blade Servers and Virtualization (Goldworm, Skamarock)
Storage Area Networks (Barker, Massiglia)
Wikipedia