On: It's time to replace TCP in the datacenter (2023)

[KaiserPro]

FC was much more expensive than ethernet, so needed a reason to be used.

For block storage it is great, if slower than ethernet.

[UltraSane → KaiserPro]

Is their a fundamental reason for it being more expensive than Ethernet or is just greed?

[KaiserPro → UltraSane]

At the time it was rarer and required more specialised hardware.

FC was one of the first non-mainframe specific storage area network fabrics. One of the key differences between FC and ethernet is the collision detection/avoidance and guaranteed throughput. All that extra coordination takes effort on big switches, so it cost more to develop/produce.

You could shovel data through it at "line speed" and know that it'll get there, or you'll get an error at the fabric level. Ethernet happily takes packets, and if it can't deliver, then it'll just drop them. (well, kinda, not all ethernet does that, because ethernet is the english language of layer 2 protocols)