Path: utzoo!utgpu!news-server.csri.toronto.edu!rpi!zaphod.mps.ohio-state.edu!swrinde!cs.utexas.edu!sun-barr!newstop!exodus!appserv!slovax.Eng.Sun.COM!lm From: lm@slovax.Eng.Sun.COM (Larry McVoy) Newsgroups: comp.protocols.nfs Subject: Re: Symlink locking considered useless over NFS Message-ID: <556@appserv.Eng.Sun.COM> Date: 23 Apr 91 01:25:55 GMT References: <98765@sgi.sgi.com> Sender: news@appserv.Eng.Sun.COM Organization: Sun Microsystems, Mt. View, CA. Lines: 21 vjs@rhyolite.wpd.sgi.com (Vernon Schryver) writes: > In article , thurlow@convex.com (Robert Thurlow) writes: > > > > ... NFS over TCP isn't > > far away ... > > > NFS over TCP seems good if you're trying to get over a very slow or very > lossy link. NFS/TCP can't scale a fraction as far as NFS/UCP, despite > statements to the contrary in that other, unnamed reference. NFS/TCP seems > a generally unlikely choice. NFS/UDP works well when you are on local net. In order to make it work well over WAN's, you end up essentially reimplementing TCP algs in the code that calls UDP. There was a nice study of all this in the Dallas Usenix this winter. I think the general conclusion was that NFS/TCP was about 20% slower in the LAN case but much faster in the WAN case. The argument can be made (if it was not) that tuning TCP to get back that 20% is probably a better idea than trying to make UDP deal with WANs. --- Larry McVoy, Sun Microsystems (415) 336-7627 ...!sun!lm or lm@sun.com