From owner-freebsd-jail@FreeBSD.ORG  Wed Jun 24 12:47:32 2009
Return-Path: <owner-freebsd-jail@FreeBSD.ORG>
Delivered-To: freebsd-jail@freebsd.org
Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34])
	by hub.freebsd.org (Postfix) with ESMTP id DF0131065670
	for <freebsd-jail@freebsd.org>; Wed, 24 Jun 2009 12:47:32 +0000 (UTC)
	(envelope-from tomh@motorsport.com)
Received: from montecarlo.motorsport.com (montecarlo.motorsport.com
	[64.235.98.4]) by mx1.freebsd.org (Postfix) with ESMTP id A04DF8FC19
	for <freebsd-jail@freebsd.org>; Wed, 24 Jun 2009 12:47:32 +0000 (UTC)
	(envelope-from tomh@motorsport.com)
Received: from Cerbera (CPE000ded900fa2-CM001225449c2c.cpe.net.cable.rogers.com
	[99.254.169.57]) (authenticated bits=0)
	by montecarlo.motorsport.com (8.14.1/8.14.2) with ESMTP id
	n5OCm26k082095
	for <freebsd-jail@freebsd.org>; Wed, 24 Jun 2009 08:48:03 -0400 (EDT)
	(envelope-from tomh@motorsport.com)
From: "Tom Haapanen" <tomh@motorsport.com>
To: <freebsd-jail@freebsd.org>
References: <0c1201c9f43e$166c8450$43458cf0$@com>
	<4A41461D.4000009@modulus.org>
In-Reply-To: <4A41461D.4000009@modulus.org>
Date: Wed, 24 Jun 2009 08:47:18 -0400
Message-ID: <0c9201c9f4c9$ec3d1640$c4b742c0$@com>
MIME-Version: 1.0
Content-Type: text/plain;
	charset="us-ascii"
Content-Transfer-Encoding: 7bit
X-Mailer: Microsoft Office Outlook 12.0
Thread-Index: Acn0SCfXNxmz9alqR7a6xTJ1YmmHigAgQHkg
Content-Language: en-ca
Subject: RE: Memory usage across multiple jails
X-BeenThere: freebsd-jail@freebsd.org
X-Mailman-Version: 2.1.5
Precedence: list
List-Id: "Discussion about FreeBSD jail\(8\)" <freebsd-jail.freebsd.org>
List-Unsubscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-jail>,
	<mailto:freebsd-jail-request@freebsd.org?subject=unsubscribe>
List-Archive: <http://lists.freebsd.org/pipermail/freebsd-jail>
List-Post: <mailto:freebsd-jail@freebsd.org>
List-Help: <mailto:freebsd-jail-request@freebsd.org?subject=help>
List-Subscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-jail>,
	<mailto:freebsd-jail-request@freebsd.org?subject=subscribe>
X-List-Received-Date: Wed, 24 Jun 2009 12:47:33 -0000

Andrew Snow wrote:
> * the jails share disk cache
> * jails don't have any reserved memory so any unused memory returns to 
> the free pool of the kernel, available for disk cache
> * there is a single kernel shared across all jails
> * userland code can also be shared across jails *if* you run the code 
> from the same set of on-disk binaries (which is not the way most people 
> set up jails)
> * since there is only a single kernel all network and disk I/O from the 
> jails goes at the same speed as the host

Thanks, Andrew (and Michael) -- that sounds very good.  It certainly looks
like I should be able to achieve some resource efficiencies this way vs
running multiple physical servers.

I'm also further educated about VMware ... though that's less important for
me at the moment as I would really prefer to run the host on FreeBSD as well
(and I suspect those required guest drivers aren't available for FreeBSD,
either).

Tom