SUN and Misaligned Errors

[Klaus Becker]

> I'll spare every one the
> gory details but I have sun 490 that is acting as a NSF file server to
> about 30 sparc stations that is generating Misaligned packets under heavy
> load. After all the usual testing one might do this system is on a segment
> with it's self and a bridge to the rest of the world. In this configuration
> just the file server and the bridge on a ethernet fanout box the sun
> generates misaligned packits. Any Ideas???? You will have to reply to my
> compuserve account as I can't seem to get return mail.

We see a similar behaviour at all kinds of SUNs acting as NFS-Servers. We
did some testing and finally managed to produce misaligned packets.

It was significant, that the output error rate was low on machines which
were only acting as servers, whereas server-machines with additonal
user-processes showed high error rates.

We took my SLC acting as NFS-Server for two others and watched the error
rates (netstat -i 1).  Then we produced NFS-Traffic on this machine by
copying large files etc.  No errors could be seen on the network!

Now I moved my mouse in circles in my X-Display, which produced misaligned
packets!!

It seems to be a general bug in SUNOS with interrupt-handling.  

So I think the only way to get rid of this misalinged packets is not to
allow users or other processes on NFS-Server hosts.

Any comments from SUN?

Klaus Becker -- +497216083973 -- Becker at ira.uka.DE