How to Backup an iPhone to External Hard Drive with Mac OS X
For those of us with larger storage size iPhone and iPad models, backing up the device locally can be a burden on limited disk space. A simple solution to this storage dilemma is to backup an iPhone, iPad, or iPod touch to an external hard drive instead, where disk space is often more abundant. We’ll walk you through how to get this setup in Mac OS X, so that any locally made backup from iTunes goes to an external disk rather than the internal drive, thereby helping to preserve local disk space and offload storage requirements.