LUN – logical unit number

Short for logical unit number, LUN is a unique identifier used on a SCSI bus to distinguish between devices that share the same bus. SCSI is a parallel interface that allows up to 16 devices to be connected along a single cable. The cable and the host adapter form the SCSI bus, and this operates independently of the rest of the computer. Each of the eight devices is given a unique address by the SCSI BIOS, ranging from 0 to 7 for an 8-bit bus or 0 to 15 for a 16-bit bus. Devices that request I/O processes are called initiators. Targets are devices that perform operations requested by initiators. Each target can accommodate up to eight other devices, known as logical units, and each is assigned an LUN. Commands that are sent to the SCSI controller identify devices based on their LUNs.

Webopedia Staff
Webopedia Staff
Since 1995, more than 100 tech experts and researchers have kept Webopedia’s definitions, articles, and study guides up to date. For more information on current editorial staff, please visit our About page.
Get the Free Newsletter
Subscribe to Daily Tech Insider for top news, trends & analysis
This email address is invalid.
Get the Free Newsletter
Subscribe to Daily Tech Insider for top news, trends & analysis
This email address is invalid.

Related Articles

Complete List of Cybersecurity Acronyms

Cybersecurity news and best practices are full of acronyms and abbreviations. Without understanding what each one means, it's difficult to comprehend the significance of...

Human Resources Management System

A Human Resources Management System (HRMS) is a software application that supports many functions of a company's Human Resources department, including benefits administration, payroll,...

How To Defend Yourself Against Identity Theft

Almost every worldwide government agency responsible for identity theft issues will tell you the same thing: The first step to fighting identity theft is...

Infographic

An infographic is a visual representation of information or data. It combines the words information and graphic and includes a collection of imagery, charts,...

ScalaHosting

ScalaHosting is a leading managed hosting provider that offers secure, scalable, and affordable...

HRIS

Human resources information system (HRIS) solutions help businesses manage multiple facets of their...

Best Managed Service Providers...

In today's business world, managed services are more critical than ever. They can...