Q: 2 macs using the same library?

Hi,

You can use Home Sharing and read from one computer to another and sync purchases between them. This is easier than maintaining two different sets of files with videos, songs, etc.

Yes, that is basically the same idea but only for audio and video files. Note that since you don't want to have files in your computer, the "master" computer that is sharing contents will need to be started up.

Another option, with additional subscription cost, is iTunes Match. Using this service you don't need to have a computer on since all contents are in iCloud and you can stream or download those in any device with our iTunes account. Since I have to travel a lot, I'm seriously thinking on this one, but not decided yet.

I successfully performed these steps to move my library to a networked drive from my iMac at home...--I got the error message that the library could not be found at that location.

That because you did not successfully relocate your library.  You only relocated media.

Copy the entire iTunes folder (and in doing so all its subfolders and files) intact to the other drive.  Hold down the option (alt) key (shift on Windows) and open iTunes.  You get a prompt to create or choose a library. Choose the copied iTunes folder.

Realize, however, only one computer at a time can have the library file open or you will get an open error and will need to quit iTunes on the other computer first.  An alternative is to have what you have with media on an external drive but then copy just the library files to the second computer and then the second iTunes will have its own library file.  Of course then if you make changes to one library it will not be seen if you use the other computer so you have to decide what you need.

On top of the above is all the official sharing methods mentioned by others.

What are the iTunes library files? - http://support.apple.com/kb/HT1660

More on iTunes library files and what they do - http://en.wikipedia.org/wiki/ITunes#Media_management

What are all those iTunes files? - http://www.macworld.com/article/139974/2009/04/itunes_files.html

Where are my iTunes files located? - http://support.apple.com/kb/ht1391

iTunes works through a central library file (.itl) which contains a list of where the actual media files are located.  Media alone are not a library no more than a pile of books sitting on an empty city lot are a library without the building and catalog and support services (read my links).  Your first computer can use the media on the external because the library file still on that first computer knows you have moved them to the external and looks for them there.  However, that library file is not on the networked drive so you can't find it when you look for it on your second computer iTunes to use it  and a bunch of media files are not a "library" (for iTunes, only the .itl file is the library).

When you tell iTunes to use the library file on the networked drive any changes you make to the library will be stored in that library file on the networked drive.  Nothing will happen to any residual library files still on the computers and they will eventually become dated.  If you decide to not use a single library file (read what I said earlier) but have two files then each will basically work as a more or less independent library.  However, there can still be issues. One is what you do to one library won't reflect in the other if you add a file.  Another is if somebody delete an entry from one library or renames a track then when iTunes looks for that file on the shared drive it will be gone, or may show as a broken link, or maybe the data will suddenly change (but ratings are stored in each library file, as are play counts so not everything will change).

Just move the whole iTunes folder to the external drive. There are other files iTunes uses other than the "library" files.  When it is on there either computer can use it, but not at the same time.

You don't need to start that way once each computer has been pointed to the library it needs to use.  If you do not have the network drive attached and fully awake before you start iTunes then iTunes will default back to the internal drive for each compute and whatever residual library you happen to have there.  It might be a good idea to get rid of old libraries on both computers once things seems to be configured okay since starting to a blank library will warn you that it isn't using the correct library.  If that happens, quit iTunes and option+start again.

DJSCHNC wrote:

 

Thanks mabaeyens.  Unless I am misunderstanding how home sharing works, this looks like a good option if I want to physically transfer the files to my machine.  My preference is to keep the files off my macbook air.  Ideally when home I'd connect to the networked drive and stream music from there....The music library for the iMac AND that of my Air would both be physically located on the networked drive whereas now only that of the iMac is set up this way.

You could still Music Share.  You could keep the whole library on an external drive, or just media files as you have it now, and use it from there but share it with the second computer.  The second computer would be able to play items on the first computer which would be using the external as the ultimate source for playing music from either computer.

Distinguishing music sharing and Home Sharing - https://discussions.apple.com/thread/6056435

Music Sharing - http://support.apple.com/kb/HT2688