On Mon, 7 Jun 2010, Miles Nordin wrote:
FC has different QoS properties than Ethernet because of the buffer credit mechanism---it can exert back-pressure all the way through the fabric. same with IB, which is HOL-blocking. This is a big deal with storage, with its large blocks of bursty writes that aren't really the case for which TCP shines. I would try both and compare, if you can afford it!
FCoE is beginning to change this, with ethernet adaptors and switches which support the new features. Without the new FCoE standards, Ethernet can exert back pressure but only on a local-link level, and with long delays. You can be sure that companies like cisco will be (or are) selling FCoE hardware to compete with FC SANs. The intention is that ethernet will put fibre channel out of business. We shall see if history repeats itself.
Bob -- Bob Friesenhahn bfrie...@simple.dallas.tx.us, http://www.simplesystems.org/users/bfriesen/ GraphicsMagick Maintainer, http://www.GraphicsMagick.org/ _______________________________________________ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
