Problems with access rights to VPP in a load balanced enviroment

Some weeks ago after installing Cms5 in a load balanced enviroment a problem surfaced with access rights to the VPP-folders. The vpp files for the site was on a fileshare on a seperate server,  and after installing a site on the first webserver, we copied the files to the other server, did some web.config changes,  but the site did not work, and the error message (i do not recall the exact error message now) pointed to the VPP filepath.

After some reflection and creating a page which simulated the vpp-behaviour we discovered that while one server had access rights to the vpp-files on the other server, but the second webserver didn’t have access rights to it.

We had to use SetAcl to fix the permissions for this problem but it turns out that the installer sets explicit ntfs-permissions on the vpp-folder.

We didn’t experiment with running the installer on the webserver causing problems and its possible that it would not work because of the explicit permissions being set by the installer (they might be replaced on consecutive installs).