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From: eggert@sdcrdcf.UUCP (Paul Eggert)
Newsgroups: net.unix-wizards
Subject: Re: Just how reliable is NFS?
Message-ID: <3010@sdcrdcf.UUCP>
Date: Tue, 16-Sep-86 18:18:06 EDT
Article-I.D.: sdcrdcf.3010
Posted: Tue Sep 16 18:18:06 1986
Date-Received: Fri, 19-Sep-86 23:15:44 EDT
References: <6@cvbnet.uucp> <335@mc0.UUCP> <2428@phri.UUCP>
Reply-To: eggert@sdcrdcf.UUCP (Paul Eggert)
Distribution: world
Organization: System Development Corporation R&D, Santa Monica
Lines: 14
Keywords: UDP, NFS, TCP/IP, checksums
Summary: Flaky Ethernet board can break NFS while TCP/IP keeps working.

In article <2428@phri.UUCP> roy@phri.UUCP (Roy Smith) writes:

|NFS uses UDP as the underlying transport protocol but to improve
|performance, Sun has turned off checksumming in NFS/UDP packets.
|...	Has anybody done any studies to determine if this causes any problems?

No studies, but I have an anecdote.  Last week we had an Intel Ethernet
controller board go slightly bad on a Sun-2/120 running 3.0.  TCP/IP worked
fine, but NFS had rare bit errors without issuing any diagnostic messages.
The bit errors were in executable files, causing core dumps that were oddly
reproducible due to caching.  I wasted some time tracking this down.  Had NFS
checksummed, the problem would had been evident.

-- Paul Eggert, SDC Santa Monica