Breaking into the new APP-V 5.0 APPV format

Note:This is part of a series on App-V 5.0: Part 1 Part 2 Part 3 Part 4 Part 5

One of the new surprises to be seen in the App-V 5.0 Beta is that the old SFT format is gone, replaced by an AppV format.  So what’s up with that?

The SFT format was created for the original SoftGrid product in order to support the groundbreaking file system we created to support streaming on a block, rather than file, basis.  This file system, which we called the “Jigsaw” file system internally, was unique from any other file system due to this feature.  Most of the Softricity patents were based around this file system and it’s usage.  Any other file system, CIFS, NFS, and others, could only remotely copy entire files, but this file system could bring over portions of files on an as-needed basis.  To make use of this unique feature, we needed a file format that presented these blocks to be streamed, and this was the SFT format.

In the App-V 5.0 Beta, Microsoft has removed the Jigsaw file system, as exposed by the Q: drive, and thus also chose to eliminate the SFT format and replace it with a new AppV format.  I think that this effectivly eliminates block level streaming, but I stopped being a fan of that feature many years ago, so big loss there.  So just what is this AppV formatted file?

Basically a compressed folder.  After sequencing a new package with the 4.0 Beta, I made a copy of this .AppV file, and renamed the file extenstion to .zip.  Now I can browse and look into the APPV file.  I’m not sure if I can make any changes here, as it might be based on a compressed format with something special that I might break by saving a change, but at least I can look around.  Here is an example:

AppV format

So since the SFT format is gone, does this also mean the end of the 4GB limitation?  You betcha!

By Tim Mangan

Tim is a Microsoft MVP, and a Citrix CTP Fellow. He is an expert in App-V and MSIX.


  1. Tim, very interesting series of blogs already on v5.
    “I think that this effectivly eliminates block level streaming, but I stopped being a fan of that feature many years ago”
    May I ask what the (major) downside of block-level streaming is ?


  2. Tim

    With the removal of the .sft, q:\ drive and a quite a dramatic overhaul to app-v in 5.0 does this mean that any exisiting packages created in previous versions need to be re-resequenced?



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