From owner-freebsd-current@FreeBSD.ORG Wed Aug 10 05:54:54 2005 Return-Path: X-Original-To: freebsd-current@freebsd.org Delivered-To: freebsd-current@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id A2B1616A4AC for ; Wed, 10 Aug 2005 05:54:30 +0000 (GMT) (envelope-from glenn@antimatter.net) Received: from cobalt.antimatter.net (cobalt.antimatter.net [69.55.224.239]) by mx1.FreeBSD.org (Postfix) with ESMTP id 3F89F44BC1 for ; Tue, 9 Aug 2005 23:19:26 +0000 (GMT) (envelope-from glenn@antimatter.net) Received: from glenn-mobile.antimatter.net (216-70-228-172.cust.telepacific.net [216.70.228.172]) (authenticated bits=0) by cobalt.antimatter.net (8.13.4/8.13.4) with ESMTP id j79NJJSq000567 (version=TLSv1/SSLv3 cipher=DES-CBC3-SHA bits=168 verify=NO); Tue, 9 Aug 2005 16:19:23 -0700 Message-Id: <6.1.0.6.2.20050809161133.01beac70@cobalt.antimatter.net> X-Sender: lists@cobalt.antimatter.net X-Mailer: QUALCOMM Windows Eudora Version 6.1.0.6 Date: Tue, 09 Aug 2005 16:20:22 -0700 To: Jeremie Le Hen , drvince@anonymnet.net From: Glenn Dawson In-Reply-To: <20050809214330.GZ45385@obiwan.tataz.chchile.org> References: <20050809214330.GZ45385@obiwan.tataz.chchile.org> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii"; format=flowed X-Mailman-Approved-At: Wed, 10 Aug 2005 12:15:26 +0000 Cc: freebsd-current@freebsd.org Subject: Re: More into /etc/rc.d/jail X-BeenThere: freebsd-current@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Discussions about the use of FreeBSD-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 10 Aug 2005 05:54:56 -0000 At 02:43 PM 8/9/2005, Jeremie Le Hen wrote: >This was recently discussed in some thread. The problem with this >approach is that file backed md(4) devices are too slow to make it >standard. This is why this won't go into FreeBSD, IMHO. I experienced the same performance problem when comparing md(4) virtual disks in 5.x to vn(4) virtual disks in 4.x. The results were that md(4) file backed disks in 5.x was only about 1/3 the speed of vn(4) file backed disks in 4.x. Ultimately it turned out that newfs in 5.x creates ufs1 file systems which are quite different than the same file system created with newfs in 4.x. The most notable difference was that in 5.x each cylinder group essentially only had one cylinder in it. When a file system was created in 4.x and then mounted in 5.x using md(4), the performance was almost identical to the performance of vn(4) in 4.x. I posted a message about it on the freebsd-fs list, but never received any feedback. -Glenn