From owner-freebsd-fs@freebsd.org Tue Jul 14 10:00:25 2015 Return-Path: Delivered-To: freebsd-fs@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id D17E599B49D for ; Tue, 14 Jul 2015 10:00:25 +0000 (UTC) (envelope-from fullermd@over-yonder.net) Received: from thyme.infocus-llc.com (thyme.infocus-llc.com [199.15.120.10]) (using TLSv1 with cipher DHE-RSA-CAMELLIA256-SHA (256/256 bits)) (Client did not present a certificate) by mx1.freebsd.org (Postfix) with ESMTPS id ADF6ABF8 for ; Tue, 14 Jul 2015 10:00:25 +0000 (UTC) (envelope-from fullermd@over-yonder.net) Received: from draco.over-yonder.net (c-75-65-60-66.hsd1.ms.comcast.net [75.65.60.66]) (using TLSv1 with cipher ADH-AES256-SHA (256/256 bits)) (No client certificate requested) by thyme.infocus-llc.com (Postfix) with ESMTPSA id B96B437B5CF; Tue, 14 Jul 2015 05:00:23 -0500 (CDT) Received: by draco.over-yonder.net (Postfix, from userid 100) id 3mVy5M0lbFz1jw; Tue, 14 Jul 2015 05:00:23 -0500 (CDT) Date: Tue, 14 Jul 2015 05:00:23 -0500 From: "Matthew D. Fuller" To: accounts-ag Cc: freebsd-fs@freebsd.org Subject: Re: ZFS volume does not seem to free space for deleted files Message-ID: <20150714100023.GC96394@over-yonder.net> References: <55A4DB1D.7000404@netlabs.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <55A4DB1D.7000404@netlabs.org> X-Editor: vi X-OS: FreeBSD User-Agent: Mutt/1.5.23-fullermd.4 (2014-03-12) X-Virus-Scanned: clamav-milter 0.98.7 at thyme.infocus-llc.com X-Virus-Status: Clean X-BeenThere: freebsd-fs@freebsd.org X-Mailman-Version: 2.1.20 Precedence: list List-Id: Filesystems List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 14 Jul 2015 10:00:25 -0000 On Tue, Jul 14, 2015 at 11:49:17AM +0200 I heard the voice of accounts-ag, and lo! it spake thus: > > So according to my calculation it is using less than 20GB of space > for snapshots. Which does not make much sense to me as I clearly do > expect the deleted files to show up somewhere (I did it on > 2015-07-13). So how can the big difference to USED be explained > which reports 116G in total? I'm pretty sure you can't just add up those USED's and get a number suggesting how much space deleting them all will free up. AIUI, the USED number for a snapshot means how much that one alone is using; e.g., how much space would be freed by deleting just that one. So any blocks referenced by 2 or more wouldn't show up in those numbers. A bunch of files that have been sitting around a long time would be a good candidate for existing in most (/all) of them, so you won't see them in per-snapshot USED until you delete all but 1. -- Matthew Fuller (MF4839) | fullermd@over-yonder.net Systems/Network Administrator | http://www.over-yonder.net/~fullermd/ On the Internet, nobody can hear you scream.