From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from hapkido.dreamhost.com (hapkido.dreamhost.com [66.33.216.122]) by mail09.linbit.com (LINBIT Mail Daemon) with ESMTP id 2E931101AC79 for ; Thu, 26 Sep 2013 21:09:06 +0200 (CEST) Received: from homiemail-a7.g.dreamhost.com (mailbigip.dreamhost.com [208.97.132.5]) by hapkido.dreamhost.com (Postfix) with ESMTP id 2FC1BDE550 for ; Thu, 26 Sep 2013 12:02:43 -0700 (PDT) Received: from homiemail-a7.g.dreamhost.com (localhost [127.0.0.1]) by homiemail-a7.g.dreamhost.com (Postfix) with ESMTP id 5A61E25C074 for ; Thu, 26 Sep 2013 12:01:44 -0700 (PDT) Received: from ware.dreamhost.com (ware.dreamhost.com [64.111.127.160]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) (Authenticated sender: ewheeler@ewheeler.net) by homiemail-a7.g.dreamhost.com (Postfix) with ESMTPSA id 1FBD525C06E for ; Thu, 26 Sep 2013 12:01:44 -0700 (PDT) Date: Thu, 26 Sep 2013 12:01:40 -0700 (PDT) From: Eric Wheeler To: drbd-dev@lists.linbit.com Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; format=flowed; charset=US-ASCII Subject: [Drbd-dev] DRBD Trim/discard List-Id: "*Coordination* of development, patches, contributions -- *Questions* \(even to developers\) go to drbd-user, please." List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Hello all, We would like to run DRBD backed by thin-provisioned volumes (think ZFS or dm-thinp) which require discard support to dereference unused block allocations. (I searched around for DRBD trim/discard support with little commentary except the reference [1] below which does not apply to our use case.) Is discard support on the roadmap? What are the technical considerations for implementation? I'm guessing this would be a relatively simple patch, just need to add a discard flag to the wire protocol and pass that to the backing device (after calculating the metadata offset, if any). If you can comment on the desired implementation of such a feature and point me in the right direction I may be able to write a patch and test. Any help you can offer would be greatly appreciated! -Eric [1] http://lists.linbit.com/pipermail/drbd-user/2012-March/017987.html -- Eric Wheeler eWheeler Inc. http://www.globallinuxsecurity.pro/