From owner-freebsd-fs@FreeBSD.ORG Mon Aug 13 09:27:54 2012 Return-Path: Delivered-To: freebsd-fs@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [69.147.83.52]) by hub.freebsd.org (Postfix) with ESMTP id 26D5D106564A for ; Mon, 13 Aug 2012 09:27:54 +0000 (UTC) (envelope-from olivier@gid0.org) Received: from mail-lpp01m010-f54.google.com (mail-lpp01m010-f54.google.com [209.85.215.54]) by mx1.freebsd.org (Postfix) with ESMTP id 9C71C8FC14 for ; Mon, 13 Aug 2012 09:27:52 +0000 (UTC) Received: by lage12 with SMTP id e12so2243433lag.13 for ; Mon, 13 Aug 2012 02:27:52 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20120113; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :cc:content-type:x-gm-message-state; bh=9Ftbz27ydh/qQWQwV2ZNZlDCIVdqVzgpMoNOOsJTDow=; b=VUs2LcYf1xh5K7In7yo5dlSZwql4Gq3siDfSF3TZe1ULKJhGpFvcYzKW+eSeVL+W9V 9WAJ91062CkN2PTCaxQSwRXb/1K2dafCBHOOLsVgZ5M6tEaHUJyBxM+evJ7x/1uNu0Wh OhkRUPuIEItOnu5szigFz2AZAuNsr9yekQh0sBmzkMzsv1h+dMs1M8acpqxWyallcoCE qs/w1vhtdHIAt+pYFhooOSLvrYMwtZAoAZIZ9lcHCss2eztTpjPLAZ+TUY6l9xqOHloR 9OBqplvvxJhRz0aq2TGHd5t9xSddPWg8CNGAshb+k16yWwfYRKL3Wmag1CmEAd8UmiKA fUeQ== MIME-Version: 1.0 Received: by 10.152.105.51 with SMTP id gj19mr7835529lab.38.1344850072122; Mon, 13 Aug 2012 02:27:52 -0700 (PDT) Received: by 10.112.30.4 with HTTP; Mon, 13 Aug 2012 02:27:51 -0700 (PDT) In-Reply-To: <7BDA02A3-99ED-4F67-9B2D-5AAF1523642E@helenius.fi> References: <7BDA02A3-99ED-4F67-9B2D-5AAF1523642E@helenius.fi> Date: Mon, 13 Aug 2012 11:27:51 +0200 Message-ID: From: Olivier Smedts To: Petri Helenius Content-Type: text/plain; charset=ISO-8859-1 X-Gm-Message-State: ALoCoQkJjaNyCJDHSBFhxXE0NZcqLnP+bJ3dkCiMpxelrt29O7ESyC3SXvi15bFdGyYaOgRdGHXp Cc: freebsd-fs@freebsd.org Subject: Re: zero deleted blocks X-BeenThere: freebsd-fs@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Filesystems List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 13 Aug 2012 09:27:54 -0000 2012/8/13 Petri Helenius : > > Hi, > > Is it possible to have ZFS or UFS to zero out the deallocated blocks to facilitate VM disk compaction? > > Pete Did you try a classic "dd if=/dev/zero of=a-file-on-the-pool" ? This won't give good results if you do this on a filesystem with compression enabled. -- Olivier Smedts _ ASCII ribbon campaign ( ) e-mail: olivier@gid0.org - against HTML email & vCards X www: http://www.gid0.org - against proprietary attachments / \ "Il y a seulement 10 sortes de gens dans le monde : ceux qui comprennent le binaire, et ceux qui ne le comprennent pas."