From mboxrd@z Thu Jan 1 00:00:00 1970 From: Alexandre DERUMIER Subject: using discard from qemu guest when snapshot exist, fill the rbd layer with zeroes and use more space Date: Fri, 17 Jun 2016 11:10:54 +0200 (CEST) Message-ID: <1498621012.13671278.1466154654173.JavaMail.zimbra@oxygem.tv> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Return-path: Received: from mailpro.odiso.net ([89.248.211.110]:35577 "EHLO mailpro.odiso.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753830AbcFQJK4 (ORCPT ); Fri, 17 Jun 2016 05:10:56 -0400 Received: from localhost (localhost [127.0.0.1]) by mailpro.odiso.net (Postfix) with ESMTP id 8D78457FE1E67 for ; Fri, 17 Jun 2016 11:10:54 +0200 (CEST) Received: from mailpro.odiso.net ([127.0.0.1]) by localhost (mailpro.odiso.net [127.0.0.1]) (amavisd-new, port 10032) with ESMTP id bPujDOhTeg4v for ; Fri, 17 Jun 2016 11:10:54 +0200 (CEST) Received: from localhost (localhost [127.0.0.1]) by mailpro.odiso.net (Postfix) with ESMTP id 6AAFD57FE1E6A for ; Fri, 17 Jun 2016 11:10:54 +0200 (CEST) Received: from mailpro.odiso.net ([127.0.0.1]) by localhost (mailpro.odiso.net [127.0.0.1]) (amavisd-new, port 10026) with ESMTP id y0KT53AN8tlz for ; Fri, 17 Jun 2016 11:10:54 +0200 (CEST) Received: from mailpro.odiso.net (mailpro.odiso.net [10.1.31.111]) by mailpro.odiso.net (Postfix) with ESMTP id 4AED757FE1E67 for ; Fri, 17 Jun 2016 11:10:54 +0200 (CEST) Sender: ceph-devel-owner@vger.kernel.org List-ID: To: ceph-devel Hi, I'm using fstrim inside my qemu guests to remove unused space from the rbd storage. This is working fine, but I just notice that if a snapshot exist, It just do the reverse, it's filling the snasphot with zeroes, and the total cluster space is growing. It's is possible to avoid that ? Regards, Alexandre