App-V 5: Installing to the PVAD: Don’t do it . . . Yes . . . I said it.
If you have ever dealt with me directly as a customer, attended one of my presentations, or even simply stomached one of my diatribes in a casual, technical conversation, you have no doubt heard about one of my pet peeves (no, not “Tips –n- Tricks” – we’ll visit that another time) but the term “best practices.”
I loathe that term. I know we are guilty of it at Microsoft – so are just about every single technology-based organizations. In our ever-evolving industry, to put something down in print as THE ABSOLUTE BEST PRACTICES goes against the very nature of the word “practice.” It can seem arrogant. It implies way too much finality. It also can mean serious disruption when a practice changes. I work in a consulting practice. As products, regulations, politics, and trends change, so do our recommended practices. This is why I purposely try to use “under the current recommended practice” or simply just “current recommended practices.”
When it comes to recommended practices involving the sequencing of applications with App-V, I have been evolving my recommended practices particularly in the area of whether or not to use the PVAD. Specifically, whether to ever recommended to match the installation directory to the directory that was used for the Primary Virtual Application Directory. You may have also heard this as “Sequence to the PVAD, Install to the PVAD.”
Back in May, I expanded upon the subject of the PVAD and how it served as a placeholder for root-based files and directories (https://blogs.technet.com/b/gladiatormsft/archive/2014/05/24/app-v-5-on-sequencing-using-tokenized-paths-pvad-s-vfs-and-vfs-write-mode.aspx.) These differ from VFS-based resources (i.e. those beneath \root\vfs) in how the App-V 5 file system handles file operations. How you use the PVAD does have implications in terms of how:
- KNOWNFOLDERID’s always get translated to proper App-V Tokens
- Directories and Files get properly merged within Connection Groups
- Environment variables get properly translated
- VFS Write Mode is effective
Well after adjusting recommendations for App-V 5 regarding sequencing for connection groups, tokenization, and environment variables, I am now making the following recommendation to ensure that the above items always happens: It is best to always sequence with a fake PVAD which means create a false PVAD that will be different from the installation directory.
Now the next logical question would be: Are there any circumstances where this would create problems with newly sequenced virtual applications? I don’t think so. But I await your comments. :)