Re: TCP RDMA option to accelerate NFS, CIFS, SCSI, etc.

[David Robinson <David.Robinson@EBay.Sun.COM>]

To efficently determine boundaries within a packet stream work
must be done somewhere.  In the RDMA proposal it is up to the
clients to do the work to make the server's job easier.  In traditional
intelligent NIC cards the server does the work by parsing the headers.

It seems that the design of RDMA is backwards as it relies on changes
to the many clients to enable efficiency on the server. A traditional
intelligent NIC card with a modest amount of hardware/firmware
can handle 99+% of requests from unmodified clients.  The existence
proof is checksumming NICs and NFS accelerator boards.

For an efficient IP storage device it will have to deal with legacy IP
client stacks (no RDMA) and a competitive IP storage vendor will
implement the smart NIC described above. Why is RDMA more compelling?

	-David