Cloud Library Sync question regarding a iTune library located on an external hard drive

Hello, 

I am considering to use the cloud library sync features, but I have concern about its reliability given that I have all the music files in the itunes stored on an external hard drive. 

Can someone tell me if the procedure for setting up the cloud library sync would be any different? 

If possible, it would be really helpful if admin or others can instruct how to safely cloud sync my itunes library from my external hard drive. 

Many thanks in advance! 

Jason