[wplug] NFS mount problem

[Gentgeen]

I finally switched the two cards around.  NO CHANGE at all.  Linuxbox still showing RX-ERRs when connected to kingpin, but noone else and kingpin shows no errors at all.  

So I guess the thing to do now is remove sound/scsi/etc modules one at a time and see what happens??  Or could there be an easier way?


On Fri, 02 Jul 2004 20:06:00 -0400
Michael Skowvron <skowvron at verizon.net> wrote:

> Gentgeen wrote:
> 
> > I guess I have used the wrong term and/or have the wrong understanding. 
> > When I did consecutive 'ifconfig' while NFS was 'frozen' I could watch
> > the RX errors going up and up and up on 'linuxbox' but stayed at zero on
> > 'kingpin'.
> > So is this still a hardware problem, or something else? 
> 
> You've got yourself a real interesting problem. Receive errors almost
> always indicate a hardware problem. But you're not getting a solid
> hardware failure because we know that small, interactive traffic works
> fine even when NFS is "hung." Knowing that there are receive errors is
> much better than just knowing packets are dropped. They're being
> dropped because they are bad.
> 
> The problem is definitely related to the "amount" of data being passed
> because small NFS request sizes show no errors and larger request
> sizes get progressively worse. An important thing to remember is that
> kingpin is going to send "rsize" amount of data as fast as it can when
> it transmits. Smaller "rsize"-s mean a smaller amount of packets that
> linuxbox has to ingest at one time.
> 
> >    When rsize=8192, netstat showed RX-ERR increasing by 5 for every
> >         increase of 7 in RX-OK   
> >    When rsize=4096, netstat showed RX-ERR increasing by 1 for every
> >         increase of 2 in RX-OK
> >    When rsize=2048, netstat showed RX-ERR remaining at 0, and RX-OK
> >         increasing.
> > 
> > As a note, the above is not very scientific, just a matter of
> > continously running 'netstat -i' and doing some quick
> > math.
> 
> That's as scientific as I think you need to be. Netstat can be a
> diagnostic tool just like anything else. The numbers you are showing
> are absolutely horrible. On my network of 12 or so hosts I've got
> packet counts of over 400 million and I have 0 errors. I use a lot of
> NFS with 32K request sizes.
> 
> The problem appears to be isolated to linuxbox receiving packets. To
> confirm, you should also test kingpin for heavy receive load. Instead
> of reading data from your NFS filesystem, write a lot of data to it
> from linuxbox. Use an rsize of 4k or 8k and see if rx errors start to
> show up on kingpin.
> 
> If kingpin still doesn't show errors, the problem must be isolated to
> linuxbox. At this point, I would begin to suspect that the ethernet
> card is bad or there is some sort of interrupt servicing problem. If
> kingpin does start to show errors, it could be a bug in the receive
> packet handling of the tulip driver.
> 
> I notice that you always seem to have the problem when playing audio
> files. It could be that you don't do anything else on your NFS
> filesystem, or it could be that the audio board is effecting the PCI
> bus and corrupting data coming from the ethernet card. Maybe it's a
> funny interaction beween the audio driver and the tulip driver.
> 
> Do large file copies also hang NFS? If they do, then swap the ethernet
> cards between kingpin and linuxbox. Do the receive errors follow the
> card? If they do, bad card. If not, maybe it's an IRQ problem or some
> other resource conflict on linuxbox.
> 
> On the other hand, if NFS only hangs when playing audio files, look
> for the problem to be related in some way to the audio board or the
> audio driver in the kernel.
> 
> Whew! I'll be anxious to see what you post next!
> 
> Michael
> 
> 
> 
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