From owner-freebsd-stable@FreeBSD.ORG  Fri Sep 24 13:04:08 2010
Return-Path: <owner-freebsd-stable@FreeBSD.ORG>
Delivered-To: freebsd-stable@freebsd.org
Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34])
	by hub.freebsd.org (Postfix) with ESMTP id C228C106566B
	for <freebsd-stable@freebsd.org>; Fri, 24 Sep 2010 13:04:08 +0000 (UTC)
	(envelope-from avg@icyb.net.ua)
Received: from citadel.icyb.net.ua (citadel.icyb.net.ua [212.40.38.140])
	by mx1.freebsd.org (Postfix) with ESMTP id 189608FC1E
	for <freebsd-stable@freebsd.org>; Fri, 24 Sep 2010 13:04:07 +0000 (UTC)
Received: from odyssey.starpoint.kiev.ua (alpha-e.starpoint.kiev.ua
	[212.40.38.101])
	by citadel.icyb.net.ua (8.8.8p3/ICyb-2.3exp) with ESMTP id QAA16971;
	Fri, 24 Sep 2010 16:04:03 +0300 (EEST)
	(envelope-from avg@icyb.net.ua)
Message-ID: <4C9CA1C3.5070608@icyb.net.ua>
Date: Fri, 24 Sep 2010 16:04:03 +0300
From: Andriy Gapon <avg@icyb.net.ua>
User-Agent: Mozilla/5.0 (X11; U; FreeBSD amd64; en-US;
	rv:1.9.2.9) Gecko/20100920 Lightning/1.0b2 Thunderbird/3.1.4
MIME-Version: 1.0
To: Jeremy Chadwick <freebsd@jdc.parodius.com>,
	Leroy van Logchem <leroy.vanlogchem@gmail.com>
References: <AANLkTi=JwYZmxrQxpwNkXyZxC+ANbCXebTBpZj7c6x03@mail.gmail.com>
	<20100924123331.GA62762@icarus.home.lan>
In-Reply-To: <20100924123331.GA62762@icarus.home.lan>
X-Enigmail-Version: 1.1.2
Content-Type: text/plain; charset=ISO-8859-1
Content-Transfer-Encoding: 7bit
Cc: freebsd-stable@freebsd.org
Subject: Re: 8.1-RELEASE: [zfs] [kmem] zfs destroy snapshot results in panic:
 kmem_map too small
X-BeenThere: freebsd-stable@freebsd.org
X-Mailman-Version: 2.1.5
Precedence: list
List-Id: Production branch of FreeBSD source code <freebsd-stable.freebsd.org>
List-Unsubscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-stable>, 
	<mailto:freebsd-stable-request@freebsd.org?subject=unsubscribe>
List-Archive: <http://lists.freebsd.org/pipermail/freebsd-stable>
List-Post: <mailto:freebsd-stable@freebsd.org>
List-Help: <mailto:freebsd-stable-request@freebsd.org?subject=help>
List-Subscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-stable>,
	<mailto:freebsd-stable-request@freebsd.org?subject=subscribe>
X-List-Received-Date: Fri, 24 Sep 2010 13:04:08 -0000

on 24/09/2010 15:33 Jeremy Chadwick said the following:
> As for your questions under "Questions" -- yes you have to tune, no
> there aren't really "reliable guidelines" and I've been asking for such
> since ZFS came out for FreeBSD, but your values look fine.

I can't provide you "reliable" or "authoritative" guidelines, but I have an advice
which seems to work.

On amd64 set your vm.kmem_size to at least the amount of available memory that you
got, or even more (1.5x, 2x).
An easy way to do that (1x) is to set vm.kmem_size_scale="1".
In head this is already done automatically, MFC to stable/8 is expected.

As to arc_max/arc_min, set them based your needs according to general ZFS
recommendations.

-- 
Andriy Gapon