Tuesday 6 January 2009

Vista - Virtualization for the masses

Well, you thought that virtualization was expensive, involved evaluating  and deploying complex new technologies and possibly new ways of thinking about deployment and maintenance (shock horror).  You may also not be aware that Vista offers a level of virtualization right out of the box. Not the VMWare kind of OS level virtualization or the SoftGrid (App-V) kind of application virtualization - but the simple kind called;

folder and registry re-direction or "Folder and Registry Virtualization".


Folder and Registry Virtualization attempts to address the scenarios where an application attempts to write to a "local machine" or security protected area - and Vista automatically redirects the write (and subsequent read) request  to a user portion of the registry or a folder location in the user profile.


If you are developer type, you can find out more here: http://msdn.microsoft.com/en-gb/library/bb530198.aspx


Virtualization is pretty painless under Vista and is a great technology. However, you need to be aware that you should not rely on Registry and Folder virtualization as Microsoft states;


"As virtualization is an interim application compatibility technology, Microsoft intends to remove this form of virtualization from future versions of the Windows operating system as more applications are migrated to Windows Vista. As a result it is imperative your application does not take a hard dependency on the presence of virtualization in the system."


Microsoft has outline a few scenarios where you may need to disable Virtualization - which can be found here: http://support.microsoft.com/kb/927387


I think the biggest "gotcha" is the packaging of applications on Vista . Virtualization may cause duplicate registry and file locations in your target package as part of the snap-shot process. Not a big issue - but you will need a mechanism to checks for these duplicate registry entries and files.


Symantec has some great  coverage and demos on Virtualization which can be found here:





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