I have a timecapsule (2013 802.11ac version) with 2Tera of internal HDD and 2 tera of external HDD connected. And Ive got zero issues connecting and reading the HDDs, but after yosemite I always lose connection with the timecapsule (the wifi is still fine) after a while and I have to reconnect it, sometimes it prompts me to enter the password I set for timecapsule but sometimes it just rejects me.