Date: Mon, 02 Nov 2009 18:16:56 +0000 From: Gavin Atkinson <gavin@FreeBSD.org> To: Weldon S Godfrey 3 <weldon@excelsusphoto.com> Cc: freebsd-current@FreeBSD.org Subject: Re: FreeBSD 8.0 - network stack crashes? Message-ID: <1257185816.44755.29.camel@buffy.york.ac.uk> In-Reply-To: <alpine.BSF.2.00.0911020747560.80499@emmett.excelsus.com> References: <alpine.BSF.2.00.0911020747560.80499@emmett.excelsus.com>
next in thread | previous in thread | raw e-mail | index | archive | help
On Mon, 2009-11-02 at 10:52 -0500, Weldon S Godfrey 3 wrote:
> Up until yesterday, we have been running FreeBSD-CURRENT of 12/08. We
> started to see a couple months ago some very odd network behavior.
> Something happens to the stack that causes processes accessing the network
> to just hang. After the problem happens, usually (but not always), you
> can't ssh in. Always, you can't ssh or telnet out, and nothing can access
> the NFS shares on the server. You can ping everything from the server.
> You can't even do a route add, you can't ssh if you use just the IP
> address (although pinging with hostnames it doesn't have cached or in
> hosts table resolves). When you try to ssh out, do a route add from the
> box, the process just hangs. You can't control C it at all, it hangs
> forever. There is nothing in dmesg or messages to indicate an issue. I
> try to up/down the interfaces. In CURRENT-12/08, it may allow things to
> work for like 30s.
Some things that would be useful:
- Does "arp -da" fix things?
- What's the output of "netstat -m" while the networking is broken?
- What does CTRL-T show for the hung SSH or route processes?
- What does "procstat -kk" on the same processes show?
- Does going to single user mode ("init 1" and killing off any leftover
processes) cause the machine to start working again? If so, what's the
output of "netstat -m" afterwards?
If you look to be hitting some of the limits shown by "netstat -m", try
logging the date, "netstat -m" and "vmstat -m" to a file every 30
seconds or similar so that we can see if it is a memory leak, and what
may be leaking.
Gavin
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?1257185816.44755.29.camel>