From owner-freebsd-stable@FreeBSD.ORG Sat Aug 6 03:38:20 2011 Return-Path: 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 AC68A1065670 for ; Sat, 6 Aug 2011 03:38:20 +0000 (UTC) (envelope-from doconnor@gsoft.com.au) Received: from cain.gsoft.com.au (cain.gsoft.com.au [203.31.81.10]) by mx1.freebsd.org (Postfix) with ESMTP id 2288B8FC0A for ; Sat, 6 Aug 2011 03:38:18 +0000 (UTC) Received: from ur.dons.net.au (ppp121-45-110-64.lns20.adl6.internode.on.net [121.45.110.64]) (authenticated bits=0) by cain.gsoft.com.au (8.14.4/8.14.3) with ESMTP id p763c7Pv052557 (version=TLSv1/SSLv3 cipher=AES128-SHA bits=128 verify=NO); Sat, 6 Aug 2011 13:08:14 +0930 (CST) (envelope-from doconnor@gsoft.com.au) Mime-Version: 1.0 (Apple Message framework v1244.3) Content-Type: text/plain; charset=us-ascii From: "Daniel O'Connor" In-Reply-To: Date: Sat, 6 Aug 2011 13:08:07 +0930 Content-Transfer-Encoding: quoted-printable Message-Id: <6E45CE57-491E-4077-B14C-751C73647EFC@gsoft.com.au> References: <20110802094226.GA93114@icarus.home.lan> <42039B84-D6CE-4780-AA70-8500B1B32036@gsoft.com.au> <4E37CD13.1070402@digsys.bg> To: "Patrick M. Hausen" X-Mailer: Apple Mail (2.1244.3) X-Spam-Score: 0.163 () BAYES_00,RDNS_DYNAMIC X-Scanned-By: MIMEDefang 2.67 on 203.31.81.10 Cc: freebsd-stable@freebsd.org, Christian Weisgerber Subject: Re: ZFS directory with a large number of files X-BeenThere: freebsd-stable@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Production branch of FreeBSD source code List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sat, 06 Aug 2011 03:38:20 -0000 On 06/08/2011, at 5:17, Patrick M. Hausen wrote: > Am 05.08.2011 um 17:12 schrieb Christian Weisgerber: >> Daniel Kalchev wrote: >>=20 >>> On 02.08.11 12:46, Daniel O'Connor wrote: >>>> I am pretty sure UFS does not have this problem. i.e. once you=20 >>>> delete/move the files out of the directory its performance would be=20= >>>> good again.=20 >>>=20 >>> UFS would be the classic example of poor performance if you do this. >>=20 >> "Classic" indeed. UFS dirhash has pretty much taken care of this >> a decade ago. >=20 > While dirhash is quite an improvement, it is definitely no silver = bullet. >=20 > When I asked Kirk McKusick at last year's EuroBSDCon if having > a six-figure number of files in a single directory was a clever idea > (I just had a customer who ran into that situation), he just smiled > and shook his head. Ahh, but OP had moved these files away and performance was still poor.. = _that_ is the bug. -- Daniel O'Connor software and network engineer for Genesis Software - http://www.gsoft.com.au "The nice thing about standards is that there are so many of them to choose from." -- Andrew Tanenbaum GPG Fingerprint - 5596 B766 97C0 0E94 4347 295E E593 DC20 7B3F CE8C