Date: Wed, 2 Aug 2000 20:49:31 +0000 (GMT) From: Terry Lambert <tlambert@primenet.com> To: kris@FreeBSD.org (Kris Kennaway) Cc: tlambert@primenet.com (Terry Lambert), zzhang@cs.binghamton.edu (Zhihui Zhang), stevec@nbci.com (Steve Carlson), freebsd-fs@FreeBSD.org Subject: Re: FFS performance for large directories? Message-ID: <200008022049.NAA06177@usr06.primenet.com> In-Reply-To: <Pine.BSF.4.21.0007311744410.14596-100000@freefall.freebsd.org> from "Kris Kennaway" at Jul 31, 2000 05:45:36 PM
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> 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
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