From owner-freebsd-stable@FreeBSD.ORG Tue Oct 7 08:58:51 2003 Return-Path: Delivered-To: freebsd-stable@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 3D8EC16A4B3; Tue, 7 Oct 2003 08:58:51 -0700 (PDT) Received: from psg.com (psg.com [147.28.0.62]) by mx1.FreeBSD.org (Postfix) with ESMTP id CC18B43FAF; Tue, 7 Oct 2003 08:58:49 -0700 (PDT) (envelope-from randy@psg.com) Received: from [127.0.0.1] (helo=roam.psg.com) by psg.com with esmtp (Exim 4.24; FreeBSD 4.9) id 1A6uEb-000K7x-7r; Tue, 07 Oct 2003 15:58:49 +0000 Received: from localhost ([127.0.0.1] helo=roam.psg.com) by roam.psg.com with esmtp (Exim 4.24; FreeBSD 4.9) id 1A6u0G-000JkG-2A; Tue, 07 Oct 2003 08:44:00 -0700 From: Randy Bush MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Date: Tue, 7 Oct 2003 08:43:58 -0700 To: Don Lewis References: <200310051955.h95JtlN1049840@gw.catspoiler.org> Message-Id: cc: freebsd-stable@FreeBSD.org Subject: Re: dump faster from remote than from local X-BeenThere: freebsd-stable@freebsd.org X-Mailman-Version: 2.1.1 Precedence: list List-Id: Production branch of FreeBSD source code List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 07 Oct 2003 15:58:51 -0000 >> dump from B->A i.e. from a system on local ether >> >> DUMP: DUMP: 2082890 tape blocks on 1 volume >> DUMP: finished in 478 seconds, throughput 4357 KBytes/sec >> ^^^^^^^^^^^^^^^ >> and a local dump on A >> >> DUMP: DUMP: 3560987 tape blocks on 1 volume >> DUMP: finished in 3694 seconds, throughput 963 KBytes/sec >> ^^^^^^^^^^^^^^ >> why is local slower than remote? > > What are you dumping to on A? sorry. both dumping to a separate dump drive on sys A. > If you are dumping to a file on the same spindle, you spend a lot > more time doing long seeks. Is there other I/O occuring on the > same spindle as the filesystem that you are dumping on A? nope > Could the file system on B have a small number of large files while A > has a large number of small files? nope. both /usr on freebsd systems > What results do you get if you dump each file system to /dev/null > on the local machine? good question randy