svn commit: r197298 - head/sbin/mount_nfs

[Rick Macklem]

On Sat, 19 Sep 2009, M. Warner Losh wrote:

> :
> : Hmm, it might actually be nice to be able to change those at some point
> : as well.  I have looked at this in the past and it is quite deeply
> : buried in libc. :-/
>
> What's the benefit for forcing a tcp connection for the portmapper
> RPCs?  They just happen once at startup...
>
Someone mentioned an issue w.r.t. umount using UDP, which was basically
a slow timeout when a server didn't handle the UDP call, such as when
it was down. I'd guess that a TCP attempt would fail more quickly than
a UDP attempt when the server doesn't have rpcbind/portmapper running.
(Not so sure when the server has crashed, but I'm guessing that the TCP
connection attempt fails more quickly than the N retries over UDP?)

And what about going through NAT gateways? (I'm not familiar with how
typical NAT gateways are set up, but do they all forward UDP ok?)

I suspect others would know more about the tradeoffs? rick