<<<Can anyone explain the difference between a "director" and a switch? Thanks in advance.>>>
The difference is in flexibility. You have to pre-defined which channel connects to which storage devices for a "director". This McData Fibre channel director has 32 ports. Each device has to occupy one port and the relationship of host vs devices have to be pre-defined. You cannot extend the connections to some meaningful distance. All connections have to come to the director via a channel cable(usually is about 150'). I don't think you can daisy chain "directors" together. Each 32 ports have to be its own island.
On the other hand, the upper limit of FC switch or hub connections is hugh, it can be in the thousands. And, it can extend the connections to a few miles. Plus, logical connections can be made at the time of usage, unlike a "director", logical and physical connections have to be done before usage. Directors for conventional SCSI, ESCON protocol exist for a long time. This FC director just a natural progression of the similar thing. FC was invented for solving these very limitations imposed by conventional accessing methods. Is this "director" a competition to Ancor or FC switch/hub companies? Somewhat. But, their applications are hardly the same. Data center that does not require clustering, does not require additional storage and storage connections(in a well-planned meshing way), then this director will do. But, then again, why would this same data center bother going to FC. |
