In response to a recent post on the Microsoft SoftGrid Forums at http://technet.microsoft.com/en-us/softgrid/bb676741.aspx this Blog post has been submitted in order to lend some form of guidance to Sequencing scenarios that are beyond the “Standard Sequencing”.
The title of the post is a little ambiguous, “Advanced Sequencing”. The name implies that what we are doing here is more complex than a “Standard Sequence”. That is not really the case. What I mean by that is Sequencing through the Sequencer utility is still a 36 step process. What is really important for a topic like this is which of those steps needs to have an action taken that is a little different than the “Standard Sequence”.
In this series of posts we will address the following “Advanced Sequencing” topics:
- Sequence an application that hard codes its install to the C:\ drive
- Create a Virtual Environment for a web based application
- Perform an Open for Package Upgrade on an existing package
- Build scripts into an .OSD file
The first topic in this multi part series is performing what has been coined in the field as a “VFS of an Install”
Some applications require that they be installed to the local C:\ drive as opposed to giving the installer the choice of destination paths. It is possible to successfully sequence these applications and stream them to a client to run from the client’s virtual drive (typically Q:\). This is accomplished by performing what is called a VFS of the install.
Microsoft does not recommend Sequencing to the C:\ drive for a number of reasons. First, depending on how the Sequencing is performed, it may introduce slight or significant Microsoft SoftGrid Application Virtualization overhead. Also, the specific drive letter C:\ would be required to be present on the Microsoft SoftGrid Application Virtualization client. While this may not seem like an unusual requirement there are environments that will not meet it. For example if drives were remapped in a Microsoft SoftGrid Application Virtualization for Terminal Services environment.
What is important to keep in mind during the Sequencing of this type of application is that you are causing the entire application to be run from the Virtual File System, hence the phrase “VFS the install”. Now, to appreciate this we need to understand that during a “Standard Sequencing”, files will always be copied into the VFS. However, in a “Standard Sequence” those files are generally the ones that are copied outside of the application’s own asset directory.
For example, if you are performing a “Standard Sequence” of the SeanDo application and during its install it places the bulk of its files in the Q:\SeanDo.v1\assets directory. However, it also places a handful of files in the C:\Windows\System32 directory. The Sequencer captures that and places those handful of files in the Q:\SeanDo.v1\VFS\CSIDL_SYSTEM directory. This is “standard”.
But, if we have an application that is installed into the C:\whatever_directory , during the monitor phase of Sequencing then the entire contents of that applications assets directory will need to be copied to the Q:\pakcroot\vfs directory.
During the installation phase of the Sequencer you will create a directory on the Q:\ drive for the application to use (following the recommended best practices). Let the application install as required to the C:\ drive. After “Stop Monitoring” is clicked you will be prompted for the primary directory that the application was installed to. Here you will select the Q:\ drive and the directory that you created during the installation phase. This will cause the entire application’s assets to be copied to the VFS of this directory.
The next phase of the Sequencing is the launch application phase. During this phase you will execute the application from the virtual drive and root directory that you had created during the installation phase. This will order the blocks of code into stream able units to be delivered to the client in Feature Block 1 or Feature Block 2.