From owner-freebsd-current Mon Mar 6 00:25:49 1995 Return-Path: current-owner Received: (from majordom@localhost) by freefall.cdrom.com (8.6.10/8.6.6) id AAA26080 for current-outgoing; Mon, 6 Mar 1995 00:25:49 -0800 Received: from estienne.cs.berkeley.edu (estienne.CS.Berkeley.EDU [128.32.42.147]) by freefall.cdrom.com (8.6.10/8.6.6) with ESMTP id AAA26074; Mon, 6 Mar 1995 00:25:48 -0800 Received: from localhost (localhost [127.0.0.1]) by estienne.cs.berkeley.edu (8.6.9/8.6.9) with SMTP id AAA12037; Mon, 6 Mar 1995 00:25:23 -0800 Message-Id: <199503060825.AAA12037@estienne.cs.berkeley.edu> X-Authentication-Warning: estienne.cs.berkeley.edu: Host localhost didn't use HELO protocol To: "Jordan K. Hubbard" cc: Brian Tao , "Jordan K. Hubbard" , current@freefall.cdrom.com Subject: Re: "Sparse" files? In-reply-to: Your message of "Sun, 05 Mar 1995 23:12:55 PST." <24592.794473975@freefall.cdrom.com> Date: Mon, 06 Mar 1995 00:25:23 -0800 From: "Justin T. Gibbs" Sender: current-owner@FreeBSD.org Precedence: bulk >> I thought ffs could already compress sparse files? Apple II ProDOS >> does this, but it isn't strictly "compression". I think it simply >> doesn't bother to allocate disk blocks for any that are completed filled >> with null bytes. There's no performance hit, and this is on floppy-bound >> 1-MHz //e's and //c's... :) > >I don't think it does it on-the-fly, no. Bruce pretty much clinched >it when he pointed out that GNU cp, which linux uses by default, >automatically creates the holes and so their executables "compress" as >they're installed (or moved elsewhere). GNU tar also has support for >this and they probably leave the flag on (--sparse) by default. > >But as Bruce also points out, our block size of 8K also makes this >kind of compression scheme much less likely to be effective. > > Jordan Is there anyway to take advantage of our 1K frag size for doing this? -- Justin T. Gibbs ============================================== TCS Instructional Group - Programmer/Analyst 1 Cory | Po | Danube | Volga | Parker | Torus ==============================================