How do I connect my Drobo S (which uses firewire) and has 18 terabytes of data for Photoshop to my new iMac with only Thunderbolt connections?

How do I connect my firewire Drobo S storage with 18 terabytes of data for Photoshop with my new iMac with only Thunderbolt options? Reports on Apple's store site states that the Firewire to Thunderbolt cable sold by Apple caused caused most people's computer to freeze and crash. This is my working disc for Photoshop. Any suggestions/help?

Catherine