DS7.5 Imaging Fundamentals (Quick Start and Explanation)

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Article ID: 181665

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The purpose of this KB is to discuss the basic fundamentals around capturing and deploying a Hardware Independent image (HII).  There are several things that can be customized in this process, and several things that can be added to it.  However, this is the "basic" process, and how our tasks should be used to accomplish HII Imaging.

NOTE: The contents of this KB are written around Capture and Deploy of the Microsoft Operating Systems.  Fundamentally, the same "rules" apply to any OS, but the most commonly used are from Microsoft, and some of the steps or tools mentioned are specific to only those product, such as Sysprep and Unattend files.

 

Contents:

 

What does it take to capture and deploy an image?

Basically, the "imaging" process as we refer to it, is setting up a source computer, capturing the current state of that computer, and then replicating that to other computers, as quickly and painlessly as possible, but in a fully supportable way.

The problem is that in doing so, several things need to change, including:

  • The name of the "other" computers
  • Drivers to support different hardware on the "other" computers
  • Internal identifiers of software on the "other" computers (e.g. security identifiers, GUIDs, DSN's, etc.)

Additional goals of an administrator may also include things like adding customized software, customizing the look and feel by employee or department, and migrating data from one computer to another for existing employees.

 

How is this done?

The capture and deploy of an image is simple:

  • First, isolate the source OS and data so it is not in use (no data is being read or written to), by booting to an alternate "drive" such as a thumb-drive, RAM-drive, or even a different internal HD.
  • Use a utility to make a snapshot of all the data on the source and store it remotely.  This can be either file-based (default Symantec uses) or sector-based.
  • Once a new computer is ready, use a utility to replicate the captured data to the new system.

Resolving the "problems" above though requires a little more work, especially if we want to save a lot of time.  Recognizing the need for customizing their OS, Microsoft has developed a "standard" process for making any system unique, even if the "bits" are replicated.  A tool called "SysPrep" (short for the System Preparation Tool) will essentially re-wind a system to 1 step short of fully deployed.  The last step of installing any Microsoft Operating System is to run Mini Setup, which customizes the OS for the particular user and computer on which it has been installed.  SysPrep rewinds the installing so that this step will run again, creating unique SID's, names, time-zones, etc., for the computer.

Additionally, Microsoft has created a way to automate any of their installations.  For the Mini Setup portion of their OS installation, a file called "Unattend.XML" is used as an answer file to questions that the process would otherwise ask someone sitting and watching the process.  Populating that with the minimum required data will make the entire process hands-free.  As a bonus, the same file can also be used to call additional processes, such as a re-scan of the system for drivers, or even installing software.

NOTE: There are rumors from some, and even some published articles indicating that Sysprep may not be needed for mass deployments.  Symantec does NOT support imaging without Sysprep, and numerous cases have been reported where not using it has caused significant problems in Active Directory.

 

What then is the fundamental (Symantec recommended) process?