From owner-freebsd-geom@FreeBSD.ORG Thu Feb 10 02:39:21 2005 Return-Path: Delivered-To: freebsd-geom@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id A1B9116A4CE for ; Thu, 10 Feb 2005 02:39:21 +0000 (GMT) Received: from hosea.tallye.com (joel.tallye.com [216.99.199.78]) by mx1.FreeBSD.org (Postfix) with ESMTP id 84E7A43D39 for ; Thu, 10 Feb 2005 02:39:20 +0000 (GMT) (envelope-from lorenl@alzatex.com) Received: from hosea.tallye.com (hosea.tallye.com [127.0.0.1]) by hosea.tallye.com (8.12.8/8.12.10) with ESMTP id j1A2dJGf029632 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NO) for ; Wed, 9 Feb 2005 18:39:19 -0800 Received: (from sttng359@localhost) by hosea.tallye.com (8.12.8/8.12.10/Submit) id j1A2dJSo029630 for freebsd-geom@freebsd.org; Wed, 9 Feb 2005 18:39:19 -0800 X-Authentication-Warning: hosea.tallye.com: sttng359 set sender to lorenl@alzatex.com using -f Date: Wed, 9 Feb 2005 18:39:19 -0800 From: "Loren M. Lang" To: freebsd-geom@freebsd.org Message-ID: <20050210023919.GC29396@alzatex.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.4.1i X-GPG-Key: ftp://ftp.tallye.com/pub/lorenl_pubkey.asc X-GPG-Fingerprint: B3B9 D669 69C9 09EC 1BCD 835A FAF3 7A46 E4A3 280C Subject: Does geom_uzip act as a variable size storage device? X-BeenThere: freebsd-geom@freebsd.org X-Mailman-Version: 2.1.1 Precedence: list List-Id: GEOM-specific discussions and implementations List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 10 Feb 2005 02:39:21 -0000 How does the uzip geom work as a block device for a file system. My understanding of it is that it operates like a block device that trys to compress all data written to it using the same algorithm as used by pkzip and gzip. The problem I see with that is that not all data compresses by the same amount, some compresses more and other less, so a disk that acts as a compressor can hold different amounts of data depending on what's written to it. Filesystems like msdos and ufs2 don't support running on block devices of variable sizes as far as I know so how can I possibly format a uzip disk with a regular filesystem. I know that ufs supports being resized, but that's not the same as a block device that appears to be constantly changing size as data is being written to it so how does uzip work? Does it appear as some fixed size that may have wasted space if the data was able to compress really well, and when the data doesn't compress well enough, well, I don't know what would happen then. Am I just missing something here or can the uzip geom be dangerous depending on how it's used and what fs it's formatted as. -- I sense much NT in you. NT leads to Bluescreen. Bluescreen leads to downtime. Downtime leads to suffering. NT is the path to the darkside. Powerful Unix is. Public Key: ftp://ftp.tallye.com/pub/lorenl_pubkey.asc Fingerprint: B3B9 D669 69C9 09EC 1BCD 835A FAF3 7A46 E4A3 280C