Date: Wed, 28 Apr 1999 23:07:46 +0200 From: Milan Kopacka <mkop5230@ss1000.ms.mff.cuni.cz> To: freebsd-net@freebsd.org Subject: Out of mbuf clusters Message-ID: <Pine.SGI.4.05.9904282230190.10620-100000@beta.ms.mff.cuni.cz>
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Hallo, I'm getting "Out of mbuf clusters" kernel panic, if there are processes in the system dying and leaving many opened tcp sockets. Special attack -> forking "open tcp socket and die" processes needs time under 30 sec to bring the machine down (thousands of opened sockets). FreeBSD 3.0 or 3.1; no special tuning of GENERIC kernel, just disabling some hw drivers & so on. (K6/300, 64MB of memory, de0 eth driver) In mailing lists archives I have found an advice to tune the kernel by increasing NMBCLUSTERS. How much does it help to raise the flag higher? I'm not talking about normal load, but about such mbuf attack from non-root user. Could someone explain to me, why being out of mbuf clusters is a reason to kernel panic? thanks Milan Kopacka -- <Milan.Kopacka@st.mff.cuni.cz> To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-net" in the body of the message
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