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From: =?iso-8859-1?Q?John_B=E4ckstrand?= <sandos@home.se>
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Date: Thu, 26 Jun 2003 03:03:20 +0200
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Subject: Mbuf Clusters on 4.8
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Ive been googling quite a bit now for problems with
running out of mbuf
clusters. Im basically sending a 30k datachunk down
1000-4000 connections,
but 1000 is more than enough to quickly fill upp 8192
mbuf clusters. I also
tried setting maximum amount of mbuf clusters to 65536,
but that only made
the box hard-wire 86MB of 96MB RAM, making it just as
unsuable as a dead
machine.

Of course, when the machine runs out of mbuf clusters,
it dies. I also found
this with google:

"Finally, the fact that FreeBSD 3.x panics when it runs
out of
mbuf clusters is a well-known problem.  The solution is
to not
let it run out of mbuf clusters by configuring a
sufficient
number for them."

>From this it sounds as it is a problem that should be
fixed, but it
obviously isnt in 4.8. Is this behaviour now considered
acceptable? And if
so, doesnt this make FreeBSD extremely easy to kill
using a simple
DOS-attack? Is this "fixed" in any way on 5.1?

---
John Bäckstrand