From owner-freebsd-stable Fri Sep 28 15:14: 4 2001 Delivered-To: freebsd-stable@freebsd.org Received: from ns.yogotech.com (ns.yogotech.com [206.127.123.66]) by hub.freebsd.org (Postfix) with ESMTP id 8F05737B409 for ; Fri, 28 Sep 2001 15:13:58 -0700 (PDT) Received: from nomad.yogotech.com (nomad.yogotech.com [206.127.123.131]) by ns.yogotech.com (8.9.3/8.9.3) with ESMTP id QAA15783; Fri, 28 Sep 2001 16:13:49 -0600 (MDT) (envelope-from nate@nomad.yogotech.com) Received: (from nate@localhost) by nomad.yogotech.com (8.8.8/8.8.8) id QAA29416; Fri, 28 Sep 2001 16:13:49 -0600 (MDT) (envelope-from nate) From: Nate Williams MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Message-ID: <15284.63005.31275.606644@nomad.yogotech.com> Date: Fri, 28 Sep 2001 16:13:49 -0600 To: Kris Kennaway Cc: Nate Williams , Alessandro de Manzano , Sean Chittenden , stable@FreeBSD.ORG Subject: Re: dirpref gives massive performance boost In-Reply-To: <20010928151204.A16750@xor.obsecurity.org> References: <20010928141246.A15515@xor.obsecurity.org> <20010928232009.A29187@libero.sunshine.ale> <20010928142611.A15946@xor.obsecurity.org> <20010928143016.H29974@rand.tgd.net> <20010928233800.B29391@libero.sunshine.ale> <20010928144146.A16221@xor.obsecurity.org> <15284.62680.507872.259266@nomad.yogotech.com> <20010928151204.A16750@xor.obsecurity.org> X-Mailer: VM 6.95 under 21.1 (patch 12) "Channel Islands" XEmacs Lucid Reply-To: nate@yogotech.com (Nate Williams) Sender: owner-freebsd-stable@FreeBSD.ORG Precedence: bulk List-ID: List-Archive: (Web Archive) List-Help: (List Instructions) List-Subscribe: List-Unsubscribe: X-Loop: FreeBSD.ORG > > > > > > Well, you need to wipe the disk so that when you restore it can lay > > > > > > things out optimally from the start. > > > > > > > > > > But turning on soft-updates should be sufficient to get these performance > > > > > boosts from this point on, correct? -sc > > > > > > > > AFAIK SU is not related to the physical layout of data on disk, this is > > > > the work of UFS_DIRHASH. > > > > > > No, that's something different. > > > > > > # Directory hashing improves the speed of operations on very large > > > # directories at the expense of some memory. > > > # Warning: this is experimental code! > > > options UFS_DIRHASH > > > > > > The changes to dirpref are an improved on-disk layout policy for > > > directories (and files?) It's enabled by default because there's no > > > downside. > > > > Again, I thought DIRHASH was an in-core data structure that helps with > > cache lookups for large directories, and had no effect on the on-disk > > layout. (Hence the reason why it is 'safe' to use in -stable.) > > Yes, like I said in the text you quoted, they *are* different things. *DUH* Yeah, I was confusing dirpref and DIRHASH. My bad, sorry for the braino.... My apologies Kris! Nate To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-stable" in the body of the message