From owner-freebsd-hackers@FreeBSD.ORG Wed May 31 15:11:22 2006 Return-Path: X-Original-To: freebsd-hackers@freebsd.org Delivered-To: freebsd-hackers@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id D0E8616B190 for ; Wed, 31 May 2006 15:11:22 +0000 (UTC) (envelope-from erdgeist@erdgeist.org) Received: from elektropost.org (elektropost.org [80.237.196.4]) by mx1.FreeBSD.org (Postfix) with ESMTP id D7F8A43D7D for ; Wed, 31 May 2006 15:11:16 +0000 (GMT) (envelope-from erdgeist@erdgeist.org) Received: (qmail 3520 invoked by uid 0); 31 May 2006 15:11:17 -0000 Received: from erdgeist.org (erdgeist@erdgeist.org@80.237.196.15) by elektropost.org with AES256-SHA encrypted SMTP; 31 May 2006 15:11:17 -0000 Date: Wed, 31 May 2006 17:11:16 +0200 (CEST) From: Dirk Engling To: "Eugene M. Kim" In-Reply-To: <447DB0B1.8040206@ab.ote.we.lv> Message-ID: <20060531170726.J15476@erdgeist.org> References: <447DB0B1.8040206@ab.ote.we.lv> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII; format=flowed Cc: freebsd-hackers@freebsd.org Subject: Re: dump(8) performance X-BeenThere: freebsd-hackers@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Technical Discussions relating to FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 31 May 2006 15:11:24 -0000 On Wed, 31 May 2006, Eugene M. Kim wrote: > read throughput was exactly twice as high as the tape write throughput, > throughout the entire dump phases 4 and 5, i.e. dumping actual inodes. > Disappointing, because the tape drive utilization (%busy) was lingering > around 35%-50% for most of the time; I didn't expect the disk would be > the bottleneck. :p I had a similar experience when dumping my mailserver. In addition I noticed that for a user with >300000 files (spam mails) in one directory it caused dump to sit back and think for half an hour before proceeding. I always resolved to look into the code to find something O(x^n) but didn't have the real urge. DID someone here look into that? Regards erdgeist