FreeBSD NFS server not responding to TCP SYN packets from Linux/SunOS clients

[Jim Rees]

Tcp always throws away retransmissions.  Doesn't matter whether the data is
still in the receive socket queue or not.  The nfs server will never see
replayed requests as a result of tcp retransmission.

  The problem is "how do you make sure the nfsd threads don't start a
  request if the disk I/O subsystem is backlogged".

Isn't this simply a matter of choosing the right number of nfsd threads?