A System Deployment Image (aka SDI) is a file format used primarily with

Microsoft Microsoft Corporation is an American multinational technology corporation producing computer software, consumer electronics, personal computers, and related services headquartered at the Microsoft Redmond campus located in Redmond, Washing ...

products to contain an arbitrary

disk image A disk image, in computing, is a computer file containing the contents and structure of a disk volume or of an entire data storage device, such as a hard disk drive, tape drive, floppy disk, optical disc, or USB flash drive. A disk image is us ...

, including boot sector information.

Description

The System Deployment Image (SDI) file format is often used to allow the use of a virtual disk for startup or booting. Some versions of

Microsoft Windows Windows is a group of several proprietary graphical operating system families developed and marketed by Microsoft. Each family caters to a certain sector of the computing industry. For example, Windows NT for consumers, Windows Server for serv ...

allow for "RAM

booting In computing, booting is the process of starting a computer as initiated via hardware such as a button or by a software command. After it is switched on, a computer's central processing unit (CPU) has no software in its main memory, so som ...

", which is essentially the ability to load an SDI file into memory and then boot from it. The SDI file format also lends itself to network booting using the

Preboot Execution Environment In computing, the Preboot eXecution Environment, PXE (most often pronounced as ''pixie'', often called PXE Boot/''pixie boot''.) specification describes a standardized client–server environment that boots a software assembly, retrieved from ...

(PXE). Another usage is

hard disk A hard disk drive (HDD), hard disk, hard drive, or fixed disk is an electro-mechanical data storage device that stores and retrieves digital data using magnetic storage with one or more rigid rapidly rotating platters coated with magnet ...

imaging. The SDI file itself is partitioned into the following sections: ; Boot

BLOB Blob may refer to: Science Computing * Binary blob, in open source software, a non-free object file loaded into the kernel * Binary large object (BLOB), in computer database systems * A storage mechanism in the cloud computing platform Mic ...

: This contains the actual boot program, STARTROM.COM. This is analogous to the boot sector of a hard disk. ; Load BLOB : This typically contains

NTLDR NTLDR (abbreviation of ''NT loader'') is the boot loader for all releases of Windows NT operating system from 1993 with the release of Windows NT 3.1 up until Windows XP and Windows Server 2003. From Windows Vista onwards it was replaced by the BOO ...

and is launched by the boot BLOB. ; Part BLOB : This contains the actual boot runtime (i.e. the contents of the disk image including any Operating System Sfiles) and also includes the boot.ini (used by NTLDR) and ntdetect.com files which should be located within the root directory of the runtime. The size of the runtime cannot exceed 500 MB. In addition to this requirement the runtime must also be capable of dealing with the fact that it is booting from a ramdisk. This implies that the runtime must include the "Windows

RAM Disk Ram, ram, or RAM may refer to: Animals * A male sheep * Ram cichlid, a freshwater tropical fish People * Ram (given name) * Ram (surname) * Ram (director) (Ramsubramaniam), an Indian Tamil film director * RAM (musician) (born 1974), Dutch * Ra ...

Driver" component (specified within the boot.ini). ; Disk BLOB : This is flat HDD image starting with a MBR. It is used for hard drive imaging instead of booting. Also only Disk BLOBs can be mounted with Microsoft's utilities. SDI usually contains either Disk BLOB (HD cloning or temporary SDI) or three other of them (bootable SDI).

Windows Vista Windows Vista is a major release of the Windows NT operating system developed by Microsoft. It was the direct successor to Windows XP, which was released five years before, at the time being the longest time span between successive releases of ...

Windows PE Windows Preinstallation Environment (also known as Windows PE and WinPE) is a lightweight version of Windows used for the deployment of PCs, workstations, and servers, or troubleshooting an operating system while it is offline. It is intended t ...

2.0 boot sequence includes a boot.sdi file, which contains Part BLOB for an empty NTFS volume and a Table-of-Contents slot for the

WIM Wim is a masculine given name or a shortened form of Willem and other names and may refer to: * Wim Anderiesen (1903–1944), Dutch footballer * Wim Aantjes (1923–2015), Dutch politician * Wim Arras (born 1964), Belgian cyclist * Wim Blockmans ...

image, which is stored on a separate on-disk file.

SDI features

SDI driver

SDI files can be mounted as virtual disk drives and assigned a drive letter if an SDI driver is available to allow this. A SDI driver is a type of storage driver and is commonly used with

Windows XP Embedded Windows XP, which is the next version of Windows NT after Windows 2000 and the successor to the consumer-oriented Windows Me, has been released in several editions since its original release in 2001. Windows XP is available in many languages. In ...

SDI management

Microsoft provides a tool called the "SDI File Manager" (sdimgr.exe) which can be used for the purpose of manipulating SDI files. Some of the tasks which this tool facilitates are: * The creation of an SDI image file. * The creation of an SDI image file from an existing hard disk partition. * The verification of an existing SDI image.

SDI loader

The mechanism which allows for the creation, addition and removal of virtual disk drives. SDI Loader and Driver work with Disk BLOB.

References