From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:45608) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1WNnNa-0001WY-C7 for qemu-devel@nongnu.org; Wed, 12 Mar 2014 13:55:52 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1WNnNS-0001hU-Qb for qemu-devel@nongnu.org; Wed, 12 Mar 2014 13:55:46 -0400 Received: from mx1.redhat.com ([209.132.183.28]:8146) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1WNnNS-0001gt-AC for qemu-devel@nongnu.org; Wed, 12 Mar 2014 13:55:38 -0400 Received: from int-mx02.intmail.prod.int.phx2.redhat.com (int-mx02.intmail.prod.int.phx2.redhat.com [10.5.11.12]) by mx1.redhat.com (8.14.4/8.14.4) with ESMTP id s2CHtZ5j010610 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=OK) for ; Wed, 12 Mar 2014 13:55:36 -0400 Message-ID: <53209F95.7060905@redhat.com> Date: Wed, 12 Mar 2014 18:55:33 +0100 From: Paolo Bonzini MIME-Version: 1.0 References: <20140310161119.GA6744@redhat.com> <20140310161421.GB6744@redhat.com> <531DEEDD.20007@redhat.com> <20140311200050.GU1346@redhat.com> In-Reply-To: <20140311200050.GU1346@redhat.com> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] Trying to get fstrim / discard=unmap to work List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: "Richard W.M. Jones" Cc: qemu-devel@nongnu.org Il 11/03/2014 21:00, Richard W.M. Jones ha scritto: > However the > fstrim is suspiciously fast, so there's no way it can be scanning the > whole disk for deleted files. I don't think fstrim does what it says > in the man page. fstrim definitely has some cache inside. It may also have some bugs. But when it works, it's pretty good at making du-on-the-host almost the same as usage-in-the-guest. Paolo