Path: utzoo!utgpu!water!watmath!clyde!att!osu-cis!tut.cis.ohio-state.edu!mailrus!uflorida!gatech!utkcs2!cygnusx1!moore
From: moore@cygnusx1.cs.utk.edu (Keith Moore)
Newsgroups: comp.mail.misc
Subject: Re: central mail server
Keywords: mail NFS
Message-ID: <586@utkcs2.cs.utk.edu>
Date: 9 Oct 88 03:09:02 GMT
References: <9449@swan.ulowell.edu> <4899@umix.cc.umich.edu>
Sender: news@utkcs2.cs.utk.edu
Reply-To: moore@cygnusx1.cs.utk.edu (Keith Moore)
Organization: CS Dept -- University of TN, Knoxville
Lines: 26

In article <4899@umix.cc.umich.edu> honey@citi.umich.edu (Peter Honeyman) writes:
}i abandoned the flock/lockf/whatever approach for file system locks.  i
}put my locks in /usr/spool/mail/.lock and use the atomic link trick.
}
}not high tech, i know, but i have suns, vaxen, and rt's nfs-ed
}together, and don't want to worry about who has a lock protocol that
}works.
}
}	peter
'Scuse me, but I thought that the 'atomic link trick' was broken across NFS
mounted filesystems, due to NFS's lazy directory caching scheme.  If the
method of using lock files across NFS does indeed work, then why is that
Sun claims that sharing the /usr/spool/mail directory doesn't work until
SunOS 4.0?

We are working on adapting all of our mail user agents to use lockf()
(or is it flock()?  I can't keep 'em straight) so we can share the
spool directory.  We are also looking into using POP.  If there's an 
easier way that really works, we'd like to know about it.

[Note: running SunOS 4.x is NOT the answer...it causes more problems than
it solves, and we have other machines besides Suns.]
Keith Moore
UT Computer Science Dept.	Internet/CSnet: moore@utkcs2.cs.utk.edu
107 Ayres Hall, UT Campus	BITNET: moore@utkcs1
Knoxville Tennessee 37996-1301	Telephone: +1 615 974 0822