From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Thu, 23 Nov 2000 05:20:04 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Thu, 23 Nov 2000 05:19:48 -0500 Received: from [194.213.32.137] ([194.213.32.137]:3332 "EHLO bug.ucw.cz") by vger.kernel.org with ESMTP id ; Thu, 23 Nov 2000 05:19:28 -0500 Date: Wed, 22 Nov 2000 13:29:23 +0000 From: Pavel Machek To: Roy Sigurd Karlsbakk Cc: linux-kernel@vger.kernel.org, Frank Ronny Larsen , Frank Ronny Larsen , Jannik Rasmussen , Lars Christian Nygård Subject: Re: ext2 compression: How about using the Netware principle? Message-ID: <20001122132922.A41@toy> In-Reply-To: <3A193A12.9B384B61@karlsbakk.net> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii X-Mailer: Mutt 1.0.1i In-Reply-To: <3A193A12.9B384B61@karlsbakk.net>; from roy@karlsbakk.net on Mon, Nov 20, 2000 at 03:49:55PM +0100 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Hi! > - A file is saved to disk > - If the file isn't touched (read or written to) within days > (default 14), the file is compressed. > - If the file isn't compressed more than percent (default 20), the > file is flagged "can't compress". > - All file compression is done on low traffic times (default between > 00:00 and 06:00 hours) > - The first time a file is read or written to within the days > interval mentioned above, the file is addressed using realtime > compression. The second time, the file is decompressed and commited to > disk (uncompressed). Oops, that means that merely reading a file followed by powerfail can lead to you loosing the file. Oops. Besides: you can do this in userspace with existing e2compr. Should take less than 2 days to implement. > Results: > A minimum of CPU time is wasted compressing/decompressing files. > The average server I've been out working with have an effective > compression of somewhere between 30 and 100 per cent. Results: NOP at machines that are never on in that time, random corruption after powerfail between 0:00-6:00, .. Pavel -- Philips Velo 1: 1"x4"x8", 300gram, 60, 12MB, 40bogomips, linux, mutt, details at http://atrey.karlin.mff.cuni.cz/~pavel/velo/index.html. - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org Please read the FAQ at http://www.tux.org/lkml/