Revision as of 01:03, 31 August 2008

System Deployment Image

Description

A "System Deployment Image" (aka SDI) is a file format created by Microsoft which is used to house an arbitrary disk image, including boot sector information. Some versions of Microsoft Windows allow for "RAM booting", which is essentially the ability to load a SDI file into ram and then boot from it. The SDI file format also lends itself to network booting, using a similar mechanism. The SDI file itself is partitioned into the following sections:

Boot BLOB: 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 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 OS files) 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 Driver" component (specified within the boot.ini).

Image 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:

Creating a SDI image file.
Create an SDI image file from an existing hard disk partition.
Verify an existing SDI image.

@@ Line 14: / Line 14: @@
 * Creating a SDI image file.
 * Create an SDI image file from an existing hard disk partition.
-* Verify and existing SDI image.
+* Verify an existing SDI image.