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From: liam@cs.qmc.ac.uk (William Roberts)
Newsgroups: comp.protocols.nfs
Subject: Re: Diskless Workstations and /dev/nd
Message-ID: <813@sequent.cs.qmc.ac.uk>
Date: 23 Jan 89 18:29:55 GMT
References: <1988@cpoint.UUCP> <739@mtxinu.UUCP>
Reply-To: liam@cs.qmc.ac.uk (William Roberts)
Organization: Computer Science Dept, Queen Mary College, University of London, UK.
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In article <739@mtxinu.UUCP> ed@mtxinu.COM (Ed Gould) writes:
>Running diskless without ND involves paging to a file on the server.
>With the BSD fast file system, this is acceptably efficient.

Bear in mind that program text is NOT swapped in Berkeley 4.2
(or SunOS 3.x, 4.0) so that when a page of the program needs to
be reloaded into memory it is pulled back from the original
file; this is the reason why you can't write into a program
while it's being executed ("Text file busy"), unless of ocurse
it's on a remote file system :-)

This becomes annoying if you *do* have local disk, but are
executing binaries from a remote file system. As for ND, it is
interesting to note that the Project Athena system uses a
"block server" for its root (and usr?) partitions, which is at
the same level as ND and avoids the overheads incurred by
accessing files through their inodes, but only for a read-only
file system.
-- 

William Roberts         ARPA: liam@cs.qmc.ac.uk  (gw: cs.ucl.edu)
Queen Mary College      UUCP: liam@qmc-cs.UUCP
LONDON, UK              Tel:  01-975 5250