Date: Tue, 5 May 1998 10:26:08 +0000 (GMT) From: Chris Fanning <cfanning@jingoro.prevmed.sunysb.edu> To: freebsd-net@FreeBSD.ORG Subject: sudden MBUF problem Message-ID: <199805051026.KAA01507@jingoro.prevmed.sunysb.edu>
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All was fine and good with FreeBSD's networking (for years!) until this
last weekend.
I first noticed the problem dialed in - frequent disconnection, packets
would get delayed for a crazy amount of time, etc. In fact, it's happening
right now, but only a lot less often. It's not easy diagnosing a problem
remotely when you get kicked out every minute!
I found this in my syslog:
May 5 09:54:04 jingoro /kernel: Out of mbuf clusters - increase maxusers!
So I searched for "mbuf clusters" and found a kernel setting to increase
them. All was fine with the standard settings until this weekend, so I
was a bit puzzled. Nothing changed on the machine and it gets very light
loading.
The output of my "netstat -m" is:
4704 mbufs in use:
4434 mbufs allocated to data
4 mbufs allocated to packet headers
9 mbufs allocated to protocol control blocks
253 mbufs allocated to fragment reassembly queue headers
4 mbufs allocated to socket names and addresses
2248/2262 mbuf clusters in use
5112 Kbytes allocated to network (99% in use)
0 requests for memory denied
15 requests for memory delayed
15 calls to protocol drain routines
And my uptime right now is less than 20 minutes.
I'm guessing something's going on where I'm getting a crazy amount of mbufs
being allocated to data for no good reason.
I was running 2.2-STABLE and upgraded to 2.2.6-STABLE with the same results.
Could I be the victim of some degenerative TCP/IP attack?
I ran Ethload on my network and found no packets being specifically destined
for my MAC...
After a protocol drain, the mbuf count in use climbs a few hundred per
second until it gets to the top where it stays for a while.
Anyone have any ideas on this? Or what I can do to determine what's causing
the problem?
Thanks,
Chris
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