From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-ig0-f179.google.com ([209.85.213.179]:60231 "EHLO mail-ig0-f179.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752767AbaDWUZo (ORCPT ); Wed, 23 Apr 2014 16:25:44 -0400 Received: by mail-ig0-f179.google.com with SMTP id hl10so55652igb.6 for ; Wed, 23 Apr 2014 13:25:44 -0700 (PDT) Message-ID: <1398284721.20580.7.camel@sasami> Subject: Re: Can anyone boot a system using btrfs root with linux 3.14 or newer? From: Calvin Walton To: Kai Krakow Cc: linux-btrfs@vger.kernel.org Date: Wed, 23 Apr 2014 16:25:21 -0400 In-Reply-To: References: <000001cf5f19$ac92b2b0$05b81810$@petrovi.no-ip.info> Content-Type: text/plain; charset="UTF-8" Mime-Version: 1.0 Sender: linux-btrfs-owner@vger.kernel.org List-ID: On Wed, 2014-04-23 at 21:06 +0200, Kai Krakow wrote: > Пламен Петров schrieb: > > I'm going with the module suggestion from Marc, too. > > > /dev/sda2 / btrfs relatime,compress=zlib 0 0 > > This line looks kinda useless to me. The compress=zlib option won't be > applied at boot and cannot be changed at runtime because AFAIR btrfs does > not allow that yet. ... My understanding is that the compress= option on btrfs *can* be changed at run time. After remounting with a compress= option, later writes will be done using the newly selected algorithm. The compress= option is filesystem-wide, you cannot currently use different compress= options for different subvolumes. Mounting a subvolume with a different compress= option will change the compression algorithm for all mounted subvolumes on that filesystem. (Note that I wouldn't recommend zlib on most systems as a / filesystem - it's slow to decompress compared to lzo, so it will cause slower boots if your disk is reasonably fast.) -- Calvin Walton