One common theme in the past has been folks needing to move their sim installs to another HDD/SSD because they ran out of space on the original drive.

In case you didn't realize it, when Prepar3D added the xml scenery libraries to the age-old scenery.cfg setup, it made it easily possible to place (most) add-ons on any drive, not just the one P3D is installed on.

With a good scenery manager like Lorby-SI's free P3D Addon Manager, it's a fairly easy process.  If the scenery is already installed using the xml library (in PAOM it'll be in bright green in the scenery list when enabled), it's as simple as moving the scenery over to another drive and editing the entry or entries to reflect the new location.  If it's in the scenery.cfg, PAOM makes it almost effortless to transfer it from the scenery.cfg to the xml library, and from there, again, move it to another folder on any drive and edit the config entry to reflect the scenery's new location.

There are a few exceptions...sceneries or other add-ons that are hard-coded to reside in a subdirectory under the main P3D install might not be moveable...one example being the Simaddons Canadian sceneries, which use a configurator and feature control panel that won't work if the path is changed away from the root P3D directory.  But the vast majority of sceneries, especially those designed for P3D, can be moved--in fact, Lockheed Martin strongly recommends that add-ons *not* be installed in the sim root directory so that they remain undisturbed when P3D "point" updates are installed (e.g. P3Dv4.2 -> P3Dv4.3).

Using this method, we're no longer forced into moving the whole shooting match to a bigger drive...you can add another drive to your system and expand onto it, or if you're building/rebuilding a system, you don't have to spring for a new drive if you have several that can do the job together.

Regards

 

Further to this,

If you look here:

http://www.prepar3d.com/SDKv4/sdk/add-ons/add-on_configuration_files.html

there is a good deal of documentation on how to add stuff to P3D using the command line.

For example, I used the following two commands to add separate search directories for aircraft and for gauges:

Prepar3D.exe "-Configure: Category=SimObjects, Operation=Add, Path=M:\p3d_aircraft"

Prepar3D.exe "-Configure: Category=Gauges, Operation=Add, Path=M:\p3d_gauges"

When you add a search directory using this method, it will be added to the top of the search list - it will be searched before any other path.

These two particular choices (gauges and aircraft) are handy for stuff that ordinarily wouldn't have an installer program to set up the .xml file for you.

You can add search directories for virtually everything using this method.