From owner-freebsd-questions@FreeBSD.ORG Wed Oct 22 10:32:39 2003 Return-Path: Delivered-To: freebsd-questions@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id ACB6616A4BF for ; Wed, 22 Oct 2003 10:32:39 -0700 (PDT) Received: from nitrogen.sandridge.org (pool-151-205-195-75.cap.east.verizon.net [151.205.195.75]) by mx1.FreeBSD.org (Postfix) with ESMTP id DE41B43FB1 for ; Wed, 22 Oct 2003 10:32:38 -0700 (PDT) (envelope-from ryan@sandridge.org) Received: from [10.0.1.4] (ee.d9bccf.client.atlantech.net [207.188.217.238]) by nitrogen.sandridge.org (Postfix) with ESMTP id 7E26AC4 for ; Wed, 22 Oct 2003 13:32:37 -0400 (EDT) Mime-Version: 1.0 (Apple Message framework v606) Content-Type: text/plain; charset=US-ASCII; format=flowed Message-Id: Content-Transfer-Encoding: 7bit From: Ryan Sandridge Date: Wed, 22 Oct 2003 13:32:35 -0400 To: freebsd-questions@freebsd.org X-Mailer: Apple Mail (2.606) Subject: strange dump (dark matter?) X-BeenThere: freebsd-questions@freebsd.org X-Mailman-Version: 2.1.1 Precedence: list Reply-To: freebsd@ryansandridge.com List-Id: User questions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 22 Oct 2003 17:32:39 -0000 X-List-Received-Date: Wed, 22 Oct 2003 17:32:39 -0000 Hello all. I decided it was time to start doing backups. On Oct 7th, I did a full dump of /usr filesystem (among others), as such: # dump -0uan -f - /usr | gzip -7 > /tmp/20031007-usr-lvl0.dump.gz This seemed to work as expected, here is some info about the gz file: % gzip -l 20031007-usr-lvl0.dump.gz compressed uncompr. ratio uncompressed_name 507027476 1590855680 68.1% 20031007-usr-lvl0.dump Everything so far so good. Today (Oct 22) I tried an incremental dump, as such: # dump -5uan -f - /usr | gzip -7 > /tmp/20031022-usr-lvl5.dump.gz Here is where I start getting confused. While my other incremental backups today (/ and /var), seemed to be fine, the /usr dump was huge. Here is info about the gz file: % gzip -l 20031022-usr-lvl5.dump.gz compressed uncompr. ratio uncompressed_name 527112624 543600640 3.0% 20031022-usr-lvl5.dump This incremental backup is larger than the original full dump. Also notice that the compression ratio was 3.0%. When examining the list of files dumped, I don't see anything that could lead to a file size like this. A rough count shows that the backup should have been roughly 11MB uncompressed, compared to the 518MB uncompressed. I've tried reading up on both dump and gzip, but haven't found a clue. Perhaps I've discovered dark matter. Thanks, Ryan