[TUHS] VFS prior to 1984

[Clem Cole]

On Sat, Jul 4, 2020 at 8:07 PM Dave Horsfall <dave at horsfall.org> wrote:

> Aren't holes part of the file system semantics?
>
Exactly - and that was the problem with NFS.   Consider two write
operations.  Remember each op is a complete operation with a seek to where
it's going.  If the first fails, but the error is not reported (NFS returns
errors on close), the second operations seek over the failed write -- UNIX
puts zeros in the file.   File closes later and the size is fine of
course.  Oh yeah, whoever bothered to check for errors on close (like the
traditional SCCS or RCS commands)?

Later to try to read your file back -- it will have a bunch of zeros.
As Larry says, running a simple checksum could catch a lot of these.

Anyway, I'm going to be good and lay off a diatribe on NFS.  It sort of
worked 'good enough.'   But I will say other systems (like AFS) were much
better, in practice, but it lost the war.
Clem
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