On Thu, 5 Apr 2001, Archie Cobbs wrote:

> Archie Cobbs writes:
> > I have this machine that starts running out of mbufs every few days
> > ("looutput: mbuf allocation failed") and then crashes, and was wondering
> > if anyone else has seen similar behavior...
> >
> > For example...
> >
> >     Yesterday...
> >         $ netstat -m
> >         461/624/4096 mbufs in use (current/peak/max):
> >                 459 mbufs allocated to data
> >                 2 mbufs allocated to packet headers
> >         434/490/1024 mbuf clusters in use (current/peak/max)
> >         1136 Kbytes allocated to network (36% of mb_map in use)
> >         0 requests for memory denied
> >         0 requests for memory delayed
> >         0 calls to protocol drain routines
> >
> >     Today...
> >         $ netstat -m
> >         947/1072/4096 mbufs in use (current/peak/max):
> >                 945 mbufs allocated to data
> >                 2 mbufs allocated to packet headers
> >         920/946/1024 mbuf clusters in use (current/peak/max)
> >         2160 Kbytes allocated to network (70% of mb_map in use)
> >         0 requests for memory denied
> >         0 requests for memory delayed
> >         0 calls to protocol drain routines
> >
> > It appears that something is slowly eating up mbuf clusters.
> > The machine is on a network with continuous but very low volume
> > traffic, including some random multicast, NTP, etc. The machine
> > itself is doing hardly anything at all.
>
> Well, my current guess is that this is simply an NMBCLUSTERS problem.
> I increased NMBCLUSTERS to 8192 and it hasn't happened again yet.
>
> This machine has 5 ethernet interfaces, which must be probably more
> than the default NMBCLUSTERS can handle.

Just a datapoint... I'm running a 4.3-BETA box with 8 fxp interfaces
all on 100Mbit networks (several heavily trafficed, others spurious)
and MAXUSERS set to 128, which gives me 2560 mbuf clusters:

565/2784/10240 mbufs in use (current/peak/max):
        537 mbufs allocated to data
        28 mbufs allocated to packet headers
524/2038/2560 mbuf clusters in use (current/peak/max)
4772 Kbytes allocated to network (62% of mb_map in use)
0 requests for memory denied
0 requests for memory delayed
0 calls to protocol drain routines

Could probably use a few more mbuf clusters, since its getting
close, but read on...

<proud><grin="wide">

This box has been up for 22 days (been up for many moons before, but I
wanted to test 4.3-BETA on it... yeah, its an "old" BETA already), and
does LOTS of stuff in addition to routing across the 8 fxp interfaces,
including ipfw with over 60 static rules and many hundreds of dynamic
rules, just a little bit of NAT using natd, arpwatch and snort on
about five of the interfaces, and Squid as a HTTP proxy with about
30GB of cache doing about 30000 requests/hour on average (handles
about 60000 requests during the peak hour -- lunchtime).  It still has
plenty of power left over to run a distrubuted.net personal proxy and
chew on lots of RC5 keys as well (I love FreeBSD). :-)

</proud></grin>

Its doing pretty much the gamut of network related abuse you could do
to a box -- routing on lots of interfaces, bpfilter (two per interface
in most cases), ipfw, NAT, a fair amount of incoming and outgoing
connections -- except I'm not doing anything Netgraph related
(assuming you might be, being one who wrote it).  Maybe its related to
that?


-- Chris Dillon - [EMAIL PROTECTED] - [EMAIL PROTECTED]
   FreeBSD: The fastest and most stable server OS on the planet.
   For IA32 and Alpha architectures. IA64, PPC, and ARM under development.
   http://www.freebsd.org




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