Sourcelist in MSI

Windows Installer is a powerful tool for managing application installations. Applications that are installed through the Windows Installer service gain the automatic benefit of self-repair and configuration of user data for new users. Additionally, applications written specifically to work with Windows Installer can install individual product features to run from source (server) and install on first use.

There is a registry key to look at for finding the sourcelist

HKEY_CLASSES_ROOT\Installer\Products\{Product guid}\Sourcelist
Media - > Might have 1, 2, 3 so one depending on the sourcelitst

We can set the Sourcelist during the installation itself
“msiexec.exe /I \\Test.msi SOURCELIST=”\\SMS02\Test\sourcefiles;\\SMS04\Test\sourcefiles;\\distsvr3\myfile\sourcefiles”

About SOURCELIST Property :

The SOURCELIST property is a semicolon-delimited list of network or URL source paths to the application's installation package. This list is appended to the end of each user's existing source list for the application. The installer locates a source by enumerating the list of source paths and uses the first accessible location it finds.

This registry entry is also located at

Per-user installations :
HKCU\Software\Microsoft\Installer\Products\\SourceList

Per-machine installations :
HKLM\Software\Classes\Installer\Products\\SourceList

About source resilency
http://msdn.microsoft.com/en-us/library/aa371859(VS.85).aspx