[arch-general] NFS "updates"?

[Hauke Fath]

On Mon, 27 Apr 2020 19:25:59 +0100, Leonidas Spyropoulos via 
arch-general wrote:
> On 27/04/20, Hauke Fath wrote:
>> Re-reading, this is an Arch decision -- what is the rationale? Can 
>> anybody point me to a related discussion?
> 
> It's not, it just defaults to "Y", see patch in
> 
https://github.com/archlinux/linux/commit/b24ee6c64ca785739b3ef8d95fd6becaad1bde39

Defaulting to "disabled" strikes me as heavy-handed.

From my experience, of running a few dozen nfs clients over more than 
fifteen years, at network speeds from 100 MBit clients / 1 GBit server 
to 1 GBit clients / 10 GBit server, the real-world relevance of ip 
fragment counter overruns is debatable. From a general background of 
transmission errors [1], the effect does not seem to stand out. FTR, we 
are running nfs through a filtering router, and found udp transport to 
be much more robust in the face of router outages.

So, to summarize:

The kernel nfs developers have deprecated nfs over udp in late 2019, 
AFAICS without much debate, and without any announcement outside the 
developers' mailing-list [2]. So far, so unspectacular.

The interesting question is whether Linux distributions (Arch) should 
import this kernel change uncritically, and dump it on their 
unsuspecting users, without so much as a warning.

Given nfsv3 defaults to tcp, the "protect the innocent / think of the 
children" argument does not fly: When the admin wants to use nfs over 
udp (whether she chooses, or has to), she has to actively configure the 
mount, and take responsibility. In this light, disabling nfs over udp 
in the kernel seems patronizing to professional admins.

My question is: Where should I take the issue for further discussion? 
Is this mailing-list the right place? A forum group? Should I file a 
bug report?

Cheerio,
Hauke

[1] 
<http://conferences.sigcomm.org/sigcomm/2000/conf/paper/sigcomm2000-9-1.pdf>
[2] <https://www.spinics.net/lists/linux-nfs/msg75432.html>

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