How App-V Uses Your System Drive!

Today, our topic will be files and folders. As you probably already noticed, there is another drive (often named as Q), which is not accessible from user environment, in client machines Today we will cover the files and folders which are available by end users.

Although clients stream the application code from App-V servers, launching and using an application isn’t enough to create a seamless user experience in virtualized applications. We need to store user specific settings for each application so that when multiple users launch Outlook and customize it, each user should be able to see his custom Outlook at each run. We also need to handle App-V specific operations in your client machine. Because of all these reasons, we are creating some files and folders in your box.

Firstly, let`s list the folders then we will go through each of them.  The folders paths, which are given here, are valid for default installation and for Windows Vista English OS. However for other operating systems you can find the correct path easily. Just check your client management console, properties of Application Virtualization.


·         App-V ROOT:  C:\Program Files\Microsoft Application Virtualization Client

·         Global Data Directory:  C:\Users\Public\Documents\SoftGrid Client

·         User Data Directory:  C:\Users\username\AppData\Roaming\SoftGrid Client

·         User Data (Local Cache):  C:\Users\ username \AppData\Local\SoftGrid Client

·         Client Log:  C:\ProgramData\Microsoft\Application Virtualization Client

App-V Root

I give it a name like this because it contains the binary files which create the App-V client. You may be asking, “So, what is interesting with this folder?”  Well, we don’t have just binaries inside it. It is true that, it contains bunch of App-V DLLs , executables but also it contains useful logging information too. Sftnta.txt will be created in this folder, if you set the NtaLogMask registry key in Client/Configuration registry. This log file is useful while diagnosing especially network layer problems.

Global Data Directory

Global Data Directory folder is global to all users who use that client machine. That’s why it is under Users/Public folder. It contains common files which are used by all users. So what are these common files?

·         AppFS Storage: This folder is used by transport layer and virtualization layer of AppV Client.  .BLD, .DO , .MD and .BM files are created by transport layer directly inside the AppFS Storage folder.  These files are package specific and contain information about disconnected mode, package metadata, block map etc.. In addition to these files, AppFS Storage has folders for each package. These folders start with package name and they are created by virtualization layer to keep system specific information about packages that are used by virtualization.

·         OSD Cache: When a new OSD file comes to the client, it is parsed in a temporary storage. If parsing is completed successfully, that OSD file is moved to OSD Cache so that all users will launch the same application from same OSD file which is in Global Data Directory. Since OSD files aren’t user specific, App-V stores them under Global Data Directory.!

·         ICON Cache: This is pretty much same as OSD Cache. Each application, shortcut and file type association may have an ICON file which is associated with it.

User Data Directory

This is the User Data Directory that can be set from management console. This folder is very user specific and stores user settings per package.  When you launched an application user settings are read from the user volume .pkg files so that each user can see his customized application. An example to user setting is; if you launch an Office application and change the application environment like toolbars, next time you login, you will see the same environment that you modified.  This is because we are saving each user settings in .pkg files. These files are saved to User Data Directory when you closed the application if no other App-V component is using this file at that time.

User Data (Local Cache)

Remember that I mentioned about parsing the OSD files in a temporary location? This is the temp folder for users. When you do Publishing Refresh, OSD files are downloaded here before their real location which is Global Data Directory. After a successful parsing; if OSD file is suitable for that client, it is moved to Global Data Directory.  In addition, this folder is used as a temp directory for user package volume which is in User Data Directory.  When you launched an application, user setting file for the package is read from User Data Directory and a temporary .pkg file is created in User Data (Local Cache) folder.  After client finish using that application, updated temporary .pkg file is moved to its real location which is User Data Directory.

Client Log

This folder contains only our log file which is sftlog.txt. This is a very important file to diagnose problems. It`s logging level and path can be changed from management console.

In this post, I tried to explain you, how App-V uses your disk drive to maintain a good user experience and robust virtualized applications. Having knowledge on these folders may help you to better understand how to manage your clients. Don’t forget that you can set some of the folder paths from Client Management Console.


Emre Kanlikilicer

SDE App-V Team



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