Coupling disks having only a single controller connection to more than one controller. An adaptor interfaces an ATA disk with two interfaces to a backplane having a fiber channel backplane interface form factor. Switching logic controls the interfaces, so the ATA disk has redundant capability for connecting to controlling devices. The backplane communicates signals suitable to the ATA disk, while having the same form factor as a fiber channel disk. The backplane is coupled to a signal converter, so an ATA disk can be coupled to a fiber channel interface. The signal converter allows backplanes with ATA disks to be mixed with fiber channel disks, on one fiber channel loop. ATA disks are coupled to fiber channel backplanes, so fiber channel techniques are used to provide multiple controllers for them.