fileserver crash, potential DOS

Mitch Collinsworth mitch@ccmr.cornell.edu
Sat, 31 Mar 2001 10:38:10 -0500 (EST)


On Sat, 31 Mar 2001, Bill Zumach wrote:

> You can't get a core file. Linux does not do core dumps on multi-threaded
> processes.

Oh.  :-(  Well that would certainly explain why we haven't been able to
get one or even force one.  It's too bad Transarc doesn't know this and
kept us busy for days trying to figure out how with "We can't help you
until you send us a core file."

> Since you're still getting hit from the offending client, why
> not collect some network traffic from the offending client and suggest they
> use that for their analysis? 

Yes, we did that yesterday.  Hopefully it will help.  However there was
a response to this earlier on openafs-info from someone who claimed to
have seen this before and saying it was caused by a client machine that
changes its IP address.  We'll have to test that theory on Monday with
one of our machines.  We haven't actually seen the remote machine change
addresses since we've been logging activity, but that doesn't mean it
didn't do it in the beginning.  Curiously enough the person who reported
this being due to an address change said they switched their servers
from AFS 3.6 2.5 to OpenAFS 1.0.3 and the problem went away.  I guess
it's time to seriously consider making that move here.

-Mitch