We use a 2012 Mac Mini as a simple file server here at work, running latest version of OS X, (not server). We currently have 10 drives hooked up the machine. All Seagate. 8 of them are through a Anker USB3 hub, 2 are straight into the back of the mini. It doesn't matter how I have them hooked up, today I finally realized that some of the crashes that have been happening have been because the moment I plug in another drive (be it through the hub, or into the back of the machine) the Mini will hard crash. 10 drives work fine, 11 crashes the machine without fail. It does not matter what drive I try to plug in (we have many other externals laying around) if I plug in a 11th drive the mini will hard crash. Any ideas? The mini is a clean install, no additional apps beyond our cloud backup software.