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Re: [MiNT] Firebee Coldfire MiNT Kernel and NFS

On 02/09/2014 19:56, Vincent Rivière wrote:
Next step.

Another use case:
Linux client to FireBee server

On Linux, I use:
mount -t nfs /some/path -o rw,vers=2

It works extremely *fast* and *reliably*.
However, by looking at the sniffer, I see that it uses TCP. This is another point in favor or Markus theory.

So I tried UDP:
mount -t nfs /some/path -o rw,vers=2,udp
The UDP usage is verified with the sniffer.

With UDP, basic operations work fine and fast, but bigger operations times out. There is a problem.

By looking at the sniffer, I see duplicates from the FireBee.
And I think I found an interesting clue:
The duplicate packet is exactly 1500 bytes, it is the first one of a fragmented frame. This is confirmed by looking at the data.
But strangely, I never see the second packed, among the many duplicates.

So I believe there is a problem in mintv4e.prg, when sending big UDP frames which are fragmented: the second and others are not sent. Once again, this reminds me the UDP checksum routines. I will check them next.

As a summary, on the FireBee:
- The NFS client fails due to huge timeouts, but works better when there is screen activity.
- The NFS server is unreliable in UDP mode.

Vincent Rivière