I am setting up vxupdate on one of our master backup servers NBU 8.2 on Linux. I used nbrepo to create/add vxupdate files to the NBU repository. Due to security in our solutions, we can't execute anything in /tmp for Linux nor C:\temp for Windows. I need to edit the install script to use a different location for the installation files to run from so this will work properly. The .sja files appear to be a SourceJammer Data file (that's what Google said they were) and I need to find out how to unpack them, edit the install script, and how to rebuild the sja file pack.
If this isn't possible, I need to know how to redirect the installer to use a specified location for the install files and would like to know how to do that as well.
Not sure I'd recommend editing the vxupdate bundles, but I believe the process uses the "normal" NetBackup install sccripts wrapped up in the delivery mechanism. As such setting environment variables on the target client should allow you to change the default behaviour.
For Windows try setting a global environment variable NB_TMPDIR, and for Linux clients add this variable to the /etc/environment file (or /etc/profile file).
I've not tried this myself but worth a shot.