Re: Cannot list a particular directory through NFS with UDP

[der Mouse <mouse%Rodents-Montreal.ORG@localhost>]

> I have seen NFS fail (with the old 8K packets) on a network that was
> badly terminated (back in the 10base2 days) because the back-to-back
> packets self-collided while single packets with some spacing made it
> fine.

I recall I once had an NFS problem that exhibited itself as failures
reading files of certain sizes.  Turned out that the reader had
problems receiving packets smaller than a certain size at the Ethernet
level.  UDP and NFS overhead meant that every packet was larger than
that, but if the file size was right, the last data packet got
fragmented and the last frag got lost thanks to this.  As I recall,
the sender padded to 60 octets but the receiver required 64 - but the
exact values are rather fuzzy; this was decades ago.

Mounting with rsize=1024 hid the problem, because then no NFS packet
got hit with IP-layer fragmentation.  A TCP mount would doubtless have
worked just as well, if reliable TCP mounts had existed at the time (I
don't think they did).

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