VMware ThinApp Blog

Since we get a number of questions on how to use AppSync as well as how it can be utilized, specifically around ThinApp packaged applications such as Office or Adobe CS which are not a single executable like Firefox, Opera, or Adobe Reader, we figured it best to create a video to review how AppSync works, show how to use AppSync in general, show how to use AppSync with packaged apps having separate data container files and/or multiple entry point EXEs, and discuss what is required when needing to have clients download just the differentials vs. the whole updated ThinApp packaged app (i.e. slow links, remote/home users/etc.).

General Information

This document provides general information around using the ThinApp AppSync parameters to download ThinApp updates.

This method could be used to AppSync packages that are being streamed (accessed from a network share). Schedule the AppSync.exe on the fileserver and the fileserver is updating the packages automatically. Since we are using AppSync it is only the differences that are being downloaded and therefore you will have limited payload on the WAN/LAN.

• The .asd file is used for keeping track of when last checked the AppSync location

• The .asl file is used to keep track of how much we downloaded and it contains a list of block signatures for the new file (we use these block signatures to find blocks that we can copy from the existing old file)

• The .ase is the complete new updated file waiting to be applied as the .exe file (contains blocks both from the old .exe file and from the update file)

If a download is interrupted during AppSync it continues where it left of the next time the user launches the application.

The location of the AppSync log and cache files can be specified within package.ini and with the parameter "UpgradePath=".

UpgradePath is also used for specify the location for integer updates.

AppSync allows you to update your ThinApp applications via http or https. However, we don't always have a web infrastructure to use or perhaps we would rather use a file share or replicated share like DFS or a NAS device. With AppSync, you can use these types of locations for the AppSyncURL= field. Remember, all we need is a URL location specified for the feature to work, so if you want to use a file share, follow these guidelines for your configuration of choice.

For a UNC:

\\server\share\path\to\file "convert this to" file://server/share/path/to/file

For a Local path:

c:\path\to\local\file "convert this to" file:///c:/path/to/local/file (note there are 3 slashes following file: here)

VMware's ThinApp 4.0 product has added a new feature to the previous versions of ThinStall called AppSync. Among other things, AppSync allows for administrators to build ThinApp packages that periodically check in to a web site to see if there is an update.

Using VMware's ThinApp 4.0 AppSync feature with a Microsoft Web Server can require additional configuration to the web server as, by default, IIS 6.0 does not allow access to any file with an unknown extension.

Issue

How do you set IIS 6.0 to allow download of files such as EXE's or DAT's. By default, Microsoft's IIS 6.0 will not serve out any unknown extensions. This includes EXE and DAT. Therefore, when a user requests such file, whether it be via ThinApp or directly, IIS will reply back with a 404 status code. A look in the IIS log file will show the sub-status code of 3 meaning the complete status code is 404.3. This means that the MIME restrictions prevented the request.