From mboxrd@z Thu Jan 1 00:00:00 1970 X-Msuck: nntp://news.gmane.io/gmane.emacs.gnus.general/35534 Path: main.gmane.org!not-for-mail From: Stainless Steel Rat Newsgroups: gmane.emacs.gnus.general Subject: Re: nnml compression: state of the art? Date: Thu, 29 Mar 2001 17:26:52 -0500 Organization: The Happy Fun Ball Brigade Message-ID: <01Mar29.173100est.115492@gateway.intersys.com> References: <01Mar29.105117est.115281@gateway.intersys.com> <01Mar29.141948est.115533@gateway.intersys.com> <87bsqke4s8.fsf@wesley.springies.nom> NNTP-Posting-Host: coloc-standby.netfonds.no Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii X-Trace: main.gmane.org 1035171262 3609 80.91.224.250 (21 Oct 2002 03:34:22 GMT) X-Complaints-To: usenet@main.gmane.org NNTP-Posting-Date: Mon, 21 Oct 2002 03:34:22 +0000 (UTC) Return-Path: Original-Received: (qmail 5542 invoked by alias); 29 Mar 2001 22:27:23 -0000 Original-Received: (qmail 5537 invoked from network); 29 Mar 2001 22:27:23 -0000 Original-Received: from gateway.intersys.com (HELO intersys.com) (198.133.74.253) by gnus.org with SMTP; 29 Mar 2001 22:27:23 -0000 Original-Received: by gateway.intersys.com id <115492>; Thu, 29 Mar 2001 17:31:00 -0500 Original-To: "(ding)" X-Attribution: Rat In-Reply-To: <87bsqke4s8.fsf@wesley.springies.nom> User-Agent: Gnus/5.0808 (Gnus v5.8.8) XEmacs/21.1 (Cuyahoga Valley) Original-Lines: 49 Xref: main.gmane.org gmane.emacs.gnus.general:35534 X-Report-Spam: http://spam.gmane.org/gmane.emacs.gnus.general:35534 * Alan Shutko on Thu, 29 Mar 2001 | I disagree. I tried it on a mail folder I have around: Context: nnml files are generally ~4k, not 20MB. A more relevant example: -rw------- 1 ratinox ratinox 4974 Mar 29 17:04 test -rw------- 1 ratinox ratinox 2640 Mar 29 17:04 test.1.gz -rw------- 1 ratinox ratinox 2557 Mar 29 17:04 test.9.gz On a system like mine with 4k blocks, test requires two blocks (8k), while test.1.gz and test.9.gz require one block (4k) each. The net gain in free space is one block (4k) regardess of -1 or -9. On a system with 2k blocks, test requires three blocks (6k), while test.1.gz and test.9.gz require two blocks (4k) each. The net gain in free space is one block (2k) regardless of -1 or -9. On a system with 1k blocks, test requires five blocks (5k), while test.1.gz and test.9.gz require three blocks (3k) each. The net gain in free space is two blocks (2k) regardless of -1 or -9. On a system with 512 byte blocks, test requires 10 blocks (5k), while test.1.gz requires 6 blocks (3k) and test.2.gz requires 5 blocks (2.5k). A net savings of 512 bytes. This is reaching the point of diminishing returns, because if test were 7 bytes longer then the gzip -9 file would be slightly over 512 * 5 and require 6 blocks (3k), again for no net gain. If you have a few very large files then gzip -9 is usually better if space is the primary concern. If you have lots and lots of small files then gzip -1 is almost always better, except in a few odd cases. By the way: -rw------- 1 ratinox ratinox 4974 Mar 29 17:04 test -rw------- 1 ratinox ratinox 2640 Mar 29 17:04 test.1.gz -rw------- 1 ratinox ratinox 2623 Mar 29 17:04 test.2.gz -rw------- 1 ratinox ratinox 2607 Mar 29 17:04 test.3.gz -rw------- 1 ratinox ratinox 2561 Mar 29 17:04 test.4.gz -rw------- 1 ratinox ratinox 2557 Mar 29 17:04 test.5.gz -rw------- 1 ratinox ratinox 2557 Mar 29 17:04 test.6.gz -rw------- 1 ratinox ratinox 2557 Mar 29 17:04 test.7.gz -rw------- 1 ratinox ratinox 2557 Mar 29 17:04 test.8.gz -rw------- 1 ratinox ratinox 2557 Mar 29 17:04 test.9.gz Anything beyond -5 nets you no extra space savings for small files. -- Rat \ Do not use Happy Fun Ball on concrete. Minion of Nathan - Nathan says Hi! \ PGP Key: at a key server near you! \