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From: darryl@lemuria.MV.COM (Darryl P. Wagoner)
Newsgroups: comp.unix.wizards
Subject: Re: Another reason I hate NFS: Silent data loss!
Message-ID: <1991Jun22.152801.9774@lemuria.MV.COM>
Date: 22 Jun 91 15:28:01 GMT
References: <4339.Jun1501.31.5191@kramden.acf.nyu.edu>
Reply-To: darryl@lemuria.UUCP (Darryl P. Wagoner)
Organization: Shecora Associates, Inc. Nashua, NH
Lines: 30

In article <4339.Jun1501.31.5191@kramden.acf.nyu.edu> brnstnd@kramden.acf.nyu.edu (Dan Bernstein) writes:
>I just ran about twenty processes simultaneously, each feeding into its
>own output file in the same NFS-mounted directory. About half the data
>was lost: truncated files, blocks full of zeros, etc. The NFS client and
>NFS server both had load averages under 2, though I was pounding rather
>heavily on the network (ten TCP connections or so a second from one
>machine). The data loss was completely silent.

The only time that I have seen this happen is when there was a bug in
the NFS port or the server file system code.  Is this on Suns?  The
only other thing I could think of is that the server has too many open
files.  But this is just a SWAG!

>happen occasionally on any multiuser machine. What do Sun's protocol
>designers have against TCP? What do they think is so important that they
>have to sacrifice TCP streams, TCP reliability, TCP efficiency?

Sun's protocol has nothing against TCP or any other protocol.  It is
above the RPC layer which is above the UDP layer.  RPC can be ported
to use TCP or anyother protocol with reason.  TCP might work will with
a few clients but if you have a few hundred then hang it up.




-- 
Darryl Wagoner		darryl@lemuria.MV.COM or uunet!virgin!lemuria!darryl
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Brookline, NH 03033
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