From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mout.gmx.net ([212.227.17.20]:52035 "EHLO mout.gmx.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751984AbaJ0M4L (ORCPT ); Mon, 27 Oct 2014 08:56:11 -0400 Received: from fb07-iapwap2.physik.uni-giessen.de ([134.176.19.122]) by mail.gmx.com (mrgmx103) with ESMTPSA (Nemesis) id 0LmrZY-1YJCej2bCm-00h33c for ; Mon, 27 Oct 2014 13:56:09 +0100 From: Marc Dietrich To: linux-btrfs@vger.kernel.org Subject: nocow and compression Date: Mon, 27 Oct 2014 13:56:07 +0100 Message-ID: <2033879.2EPALEPetI@fb07-iapwap2> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Sender: linux-btrfs-owner@vger.kernel.org List-ID: Hi, I created a filesystem and mounted it with compress-force=lzo. Then I did: # df -h . Filesystem Size Used Avail Use% Mounted on /dev/loop0 100M 4.1M 96M 5% /mnt # yes "Hello World" | dd of=/mnt/test iflag=fullblock bs=1M count=20 status=none yes: standard output: Broken pipe yes: write error # sync; ls -l ; df -h . total 20480 -rw-r--r-- 1 root root 20971520 Oct 27 13:48 test Filesystem Size Used Avail Use% Mounted on /dev/loop0 100M 4.7M 96M 5% /mnt so far so good ... # touch test2; chattr +C test2 # dd if=test of=test2 conv=notrunc bs=1M iflag=fullblock oflag=append status=none # sync; ls -l ; df -h . total 40960 -rw-r--r-- 1 root root 20971520 Oct 27 13:51 test -rw-r--r-- 1 root root 20971520 Oct 27 13:51 test2 Filesystem Size Used Avail Use% Mounted on /dev/loop0 100M 25M 76M 25% /mnt oops, no compression. Is this intended? Marc