Re: Cannot list a particular directory through NFS with UDP

[Jeremie Le Hen <jeremie%le-hen.org@localhost>]

Hi Greg,

Thanks for you enlightened reply.

On Sun, Feb 07, 2010 at 09:41:11AM -0500, Greg Troxel wrote:
> 
> I would suggest that you run 'netstat -s' on the netbsd box before and
> after the failed ls and diff them to see what counters are increasing.
> In particular see fragments received and reassembled.  But saving them
> both to a file and diff is often very illuminating.

I've attached the output to this mail.  I don't see anything that seems
relevant to fragment handling.

> Also, are you running a firewall that might perhaps be blocking
> fragments?  Dump firewall counters before and after.
> Also, run tcpdump with -s1500 on both the freebsd and netbsd boxes, and
> see if there are any missing packets on one vs the other.  It wasn't
> clear to me from your message that the dump was taken on the netbsd
> side.

pf was enabled on NetBSD client, but everything is allowed and scrubbing
is disabled.  I've just tried to enable scrubbing so that pf(4) handles
reassembling and the kernel issued the following message little time
afterward:
    nfs server obiwan:/data/repos: is alive again

I've done what you asked and compared the captured packets on both the
FreeBSD and NetBSD boxes: they are stricly identical, no packet is
missing.

Thanks.
Regards,
-- 
Jeremie Le Hen

Humans are born free and equal.  But some are more equal than the others.
                                            Coluche

31c31
<       116744279 total packets received
---
>       116744516 total packets received
46c46
<       90677955 packets for this host
---
>       90677988 packets for this host
48c48
<       25941807 packets forwarded (0 packets fast forwarded)
---
>       25942009 packets forwarded (0 packets fast forwarded)
52c52
<       111633452 packets sent from this host
---
>       111633483 packets sent from this host
61,62c61,62
<       110700269 packets sent
<               75549761 data packets (91016942900 bytes)
---
>       110700284 packets sent
>               75549773 data packets (91016946467 bytes)
64c64
<               32329777 ack-only packets (36623189 delayed)
---
>               32329780 ack-only packets (36623194 delayed)
70,71c70,71
<       89718493 packets received
<               26084945 acks (for 91016824081 bytes)
---
>       89718511 packets received
>               26084957 acks (for 91016827648 bytes)
74c74
<               66807336 packets (89926031191 bytes) received in-sequence
---
>               66807343 packets (89926031562 bytes) received in-sequence
92c92
<       23783848 segments updated rtt (of 16996361 attempts)
---
>       23783860 segments updated rtt (of 16996366 attempts)
100c100
<       62900564 correct data packet header predictions
---
>       62900570 correct data packet header predictions
125c125
<       428611 datagrams received
---
>       428626 datagrams received
132,134c132,134
<       419610 delivered
<       356246 PCB hash misses
<       559415 datagrams output
---
>       419625 delivered
>       356261 PCB hash misses
>       559431 datagrams output
152,153c152,153
<       97294352 SPD cache lookups
<       11661676 SPD cache misses
---
>       97294407 SPD cache lookups
>       11661718 SPD cache misses
227,228c227,228
<       110700269 packets sent
<               75549761 data packets (91016942900 bytes)
---
>       110700284 packets sent
>               75549773 data packets (91016946467 bytes)
230c230
<               32329777 ack-only packets (36623189 delayed)
---
>               32329780 ack-only packets (36623194 delayed)
236,237c236,237
<       89718493 packets received
<               26084945 acks (for 91016824081 bytes)
---
>       89718511 packets received
>               26084957 acks (for 91016827648 bytes)
240c240
<               66807336 packets (89926031191 bytes) received in-sequence
---
>               66807343 packets (89926031562 bytes) received in-sequence
258c258
<       23783848 segments updated rtt (of 16996361 attempts)
---
>       23783860 segments updated rtt (of 16996366 attempts)
266c266
<       62900564 correct data packet header predictions
---
>       62900570 correct data packet header predictions
318,319c318,319
<       97294352 SPD cache lookups
<       11661676 SPD cache misses
---
>       97294407 SPD cache lookups
>       11661718 SPD cache misses