For ISVs
White Papers
Video Garden

Setup Source Content and Links Shares

After App-V virtual applications are sequenced, they will need to be stored on an accessible file share. While administrators will need write access to this share (to add or update packages), standard users should only have read access.

So here is a screenshot of our main source content folder. You can see that we have many packages stored here, including a lot of obsolete packages and packages that are in test.

I prefer to also set up a secondary share. This share is established on a Windows 2008 (or above) server, and the share is not populated with copies of the packages, but instead symbolic-links to the folders in the main share. By having the App-V clients point to this share of links, this allows us to release only a subset of the main content share into production, plus enhances the ability to update packages by manipulating the link.

If you are not familiar yet with symbolic-links, Microsoft introduced them with Server 2008 and Windows Vista. Links may be links to individual files, or to entire folders (which is what we will use here). These links are created using the "mklink" command from a command prompt.

And here is a screenshot of our content links folder. You can see that only 14 of the packages are linked here.

If you are thinking, "that's just like a shortcut", you would be wrong. Shortcuts only apply to the local system, whereas symbolic links can involve remote systems, which is what we need.

When an application references a symbolic-link, it will be redirected to the ultimate source. Of importance to us is that any lock placed on a file will be placed on the file that the application was redirected to, and not the link. This allows us to delete and re-create the link, even though an application has placed a lock. Thus applications that are open will continue to work with the old file, while new application sessions will be remoted to the new file.

Here is an example of creating a new link to a new folder.

By default, Windows Vista and Windows 7 are configured to only follow symbolic-links that are on their own disks and then only if the link is also on this system. This is referred to as a "local to local" link. In our use, the link will be remote to the VDI desktop using it, and it will point to another share that is also remote (from the VDI image perspective). This is referred to as "remote-to-remote".

It is necessary to modify this setting in the VDI Golden image. (Note: even if you choose to not use the symbolic-links for this source folder redirection, we will need this capability turned on for the app-v cache later on). This modification can be made via group policy or using the fsutil utility from the command prompt.

For example, to enable the remote-to-remote setting, issue the following command:

fsutil behavior set SymLinkEvaluation R2R:1

You can also query the current settings:

Return to Preparation of Golden Image