From owner-freebsd-fs Mon May 6 10: 3:20 2002 Delivered-To: freebsd-fs@freebsd.org Received: from avocet.prod.itd.earthlink.net (avocet.mail.pas.earthlink.net [207.217.120.50]) by hub.freebsd.org (Postfix) with ESMTP id 0411B37B406 for ; Mon, 6 May 2002 10:03:15 -0700 (PDT) Received: from pool0013.cvx22-bradley.dialup.earthlink.net ([209.179.198.13] helo=mindspring.com) by avocet.prod.itd.earthlink.net with esmtp (Exim 3.33 #2) id 174lsv-00059v-00; Mon, 06 May 2002 10:02:50 -0700 Message-ID: <3CD6B71C.C0A502A1@mindspring.com> Date: Mon, 06 May 2002 10:02:20 -0700 From: Terry Lambert X-Mailer: Mozilla 4.7 [en]C-CCK-MCD {Sony} (Win98; U) X-Accept-Language: en MIME-Version: 1.0 To: Philip Homburg Cc: fs@FreeBSD.ORG Subject: Re: Filesystem References: <200205040019.UAA13780@illustrious.cnchost.com> <3CD32F43.327CDA46@mindspring.com> <20020504041936.GA19646@quic.net> <3CD3FB02.3EC1DA29@mindspring.com> <20020505084827.GA3688@quic.net> Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Sender: owner-freebsd-fs@FreeBSD.ORG Precedence: bulk List-ID: List-Archive: (Web Archive) List-Help: (List Instructions) List-Subscribe: List-Unsubscribe: X-Loop: FreeBSD.org Philip Homburg wrote: > >From an O.S. point of view, what's the problem with providing large > directories? Some tools, such as ls and find, may need some attention due to > scaling issues. Backup software is needed to handle the new filesystem > layout. #1 Binary backwards compatability with millions of installed systems > If somebody would like to create 1M files, and you know that, when properly > implemented, directories accesses cost O(log(n)), then what's the problem? #1 No one has written the code to optionally store directories this way (and made it publically available) #2 (minor nit) A btree is O(log2(N)), which is not as happy a number as your O(log(N)) > I know from experience that implementing a directory as a btree is trivial > if lower layers of the filesystem have (rudimentary) transaction support. #1 Bell the cat > I don't want to think about crash recovery of btrees in a normal FFS > filesystem. No one does, except the people asking us to switch to their pet FS by default, but not releasing it under a usable license, and expecting that we would just "eat" the backward compatability issue. -- Terry To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-fs" in the body of the message