Help consolidating library?

1) Not directly. If you're good at Applescript or Automator you could write an app which would start iTunes for you but only if it detects the drive is present. Click on the app instead of iTunes directly and it would only start if everything is ready to go.

2) You should not have to do any "consolidating"; something doesn't sound right. When you say you keep your library on the external drive do you mean your whole iTunes folder and everything in it (your library), or do you mean just media (which is not your "library")? What you need to do will depend greatly upon the the terminology you are using.

As far as I can tell it looks like your library (iTunes Library.itl and related files) is on your interal drive but you have media set to go to an external drive. In that scenario iTunes should start up but present you with a bunch of exclamation marks for all your broken links if the external drive is not attached. My understanding is it will still put items on the external drive. If, however, you have items you downloaded accidentally to your internal drive and you reconfigure iTunes to save media on the external drive and have the "organize" feature selected it will spend time consolidating (copying) items to the extenral drive.

Unless you have reason to keep your library split this way I would change it so it is all on the external drive. It may then work (I have not tried this and don't want to spend time testing on my ocmputer) if you simply created an alias of your library file and alwys started iTunes by clicking on that instead of the application itself. If the alias points to the library file on an external drive and that drive is not attached you will get an error message. This will remind you to turn on the drive first.

Re-uniting everything is relatively simple so let us know if you're interested in doing that.

Try moving the whole iTunes folder on your internal drive to the desired location on the external. Start iTunes with the option/alt key held down and point it to the "iTunes Library.itl" in the moved folder. This should get iTunes working on the external.

It would be nice to get it all inside the main iTunes folder so future moves simply involve copying the whole iTunes folder. To do that you can change preferences back to 'default' to store your media inside your iTunes folder. However, I haven't done this (and I use a much older version of iTunes) so I am not sure what it regards as default. If it is clever it should regard default as inside the iTunes folder on the external drive since that's where the library you are using is now located, not everything back on your internal drive Home folder! Let it consolidate to a media folder inside the moved iTunes folder if you have room since consolidating copies (you can get rid of the copied files later).

According to what somebody else said in another topic like this, if you start iTunes and it cannot find a library it will ask you to choose one, or give you other options such as quit before defaulting to an internal library. That person found that sufficient reminder to start their external drive before restarting iTunes.