From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mondschein.lichtvoll.de ([194.150.191.11]:34531 "EHLO mail.lichtvoll.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932160AbcIKTNa (ORCPT ); Sun, 11 Sep 2016 15:13:30 -0400 Received: from merkaba.localnet (ppp-93-104-51-236.dynamic.mnet-online.de [93.104.51.236]) (using TLSv1 with cipher ECDHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by mail.lichtvoll.de (Postfix) with ESMTPSA id C400C703 for ; Sun, 11 Sep 2016 21:13:28 +0200 (CEST) From: Martin Steigerwald To: linux-btrfs@vger.kernel.org Subject: Re: Small fs Date: Sun, 11 Sep 2016 21:13:28 +0200 Message-ID: <14309857.N6fGUh6qoJ@merkaba> In-Reply-To: References: <5440522.9CHaGU5Wjs@merkaba> MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Sender: linux-btrfs-owner@vger.kernel.org List-ID: Am Sonntag, 11. September 2016, 16:44:23 CEST schrieb Duncan: > * Metadata, and thus mixed-bg, defaults to DUP mode on a single-device > filesystem (except on ssd where I actually still use it myself, and > recommend it except for ssds that do firmware dedupe). In mixed-mode > this means two copies of data as well, which halves the usable space. > > IOW, when using mixed-mode, which is recommended under a gig, and dup > replication which is then the single-device default, effective usable > space is **HALVED**, so 256 MiB btrfs size becomes 128 MiB usable. (!!) I donīt get this part. That is just *metadata* being duplicated, not the actual *data* inside the files. Or am I missing something here? -- Martin