From owner-freebsd-fs Wed Aug 2 13:50:11 2000 Delivered-To: freebsd-fs@freebsd.org Received: from smtp01.primenet.com (smtp01.primenet.com [206.165.6.131]) by hub.freebsd.org (Postfix) with ESMTP id 72F2D37BBE2; Wed, 2 Aug 2000 13:49:56 -0700 (PDT) (envelope-from tlambert@usr06.primenet.com) Received: (from daemon@localhost) by smtp01.primenet.com (8.9.3/8.9.3) id NAA02528; Wed, 2 Aug 2000 13:49:30 -0700 (MST) Received: from usr06.primenet.com(206.165.6.206) via SMTP by smtp01.primenet.com, id smtpdAAAklaOWe; Wed Aug 2 13:49:16 2000 Received: (from tlambert@localhost) by usr06.primenet.com (8.8.5/8.8.5) id NAA06177; Wed, 2 Aug 2000 13:49:31 -0700 (MST) From: Terry Lambert Message-Id: <200008022049.NAA06177@usr06.primenet.com> Subject: Re: FFS performance for large directories? To: kris@FreeBSD.org (Kris Kennaway) Date: Wed, 2 Aug 2000 20:49:31 +0000 (GMT) Cc: tlambert@primenet.com (Terry Lambert), zzhang@cs.binghamton.edu (Zhihui Zhang), stevec@nbci.com (Steve Carlson), freebsd-fs@FreeBSD.org In-Reply-To: from "Kris Kennaway" at Jul 31, 2000 05:45:36 PM X-Mailer: ELM [version 2.5 PL2] MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Sender: owner-freebsd-fs@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.org > On Tue, 1 Aug 2000, Terry Lambert wrote: > > > A third thing is that FFS performs poor accessing /usr/ports. This has > > > something to do with how FFS layout directory inode (not file inode). The > > > book 4.4 BSD design and implementation explains this well. If fact, read > > > that book carefully, you can have better idea than you can get from a > > > mailing list. Good luck! > > > > This is because the tarball is packed up in the wrong order; > > change the packing order (breadth-first vs. depth-first), > > and the "ports problem" goes away. I have done this with the > > -T option to tar, and it works fine, so long as you have an > > accurate file. This ensures that there is no cache-busting > > on the dearchive, which is the source of the problem. > > Actually I benchmarked this a while back and it didn't make a significant > difference. I have SCSI drives, so maybe that's the difference, but I was sure that only using directory components whose inodes and data were already cached would have some positive effect, and attributed the effect I saw to that, since the original problem evidenced on SCSI drives as well... Terry Lambert terry@lambert.org --- Any opinions in this posting are my own and not those of my present or previous employers. To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-fs" in the body of the message