From mboxrd@z Thu Jan 1 00:00:00 1970 From: Christopher James Halse Rogers Subject: Re: bcachefs with cache device and backing device Date: Wed, 18 May 2016 15:06:39 +1000 Message-ID: <1463547999.21115.1@mail.cooperteam.net> References: <573532E2.1040201@gemtalksystems.com> <20160513043603.GA1407@kmo-pixel> <573BD789.9030406@gemtalksystems.com> <20160518040103.GA13870@moria.home.lan> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8; format=flowed Return-path: Received: from mail.cooperteam.net ([150.101.105.211]:37074 "EHLO mail.cooperteam.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750760AbcERFMp (ORCPT ); Wed, 18 May 2016 01:12:45 -0400 In-Reply-To: <20160518040103.GA13870@moria.home.lan> Sender: linux-bcache-owner@vger.kernel.org List-Id: linux-bcache@vger.kernel.org To: Kent Overstreet Cc: Martin McClure , linux-bcache@vger.kernel.org On Wed, May 18, 2016 at 2:01 PM, Kent Overstreet wrote: > On Tue, May 17, 2016 at 07:46:33PM -0700, Martin McClure wrote: >> On 05/12/2016 09:36 PM, Kent Overstreet wrote: >> > >> > Yeah - tiering replaces cache/backing devices >> > >> > IIRC, >> > >> > bcache format --tier 0 -C --tier 1 -C >> > >> > (the -C is going to go away at some point) >> > >> >> Had a chance to play with this some more, but still not getting it >> to >> work... >> >> Formatting seems to work, and once I do this: >> >> echo /dev/sdd1 > /sys/fs/bcache/register >> echo /dev/nvme0n1 > /sys/fs/bcache/register >> echo 1 > /sys/fs/bcache//blockdev_volume_create >> >> a /dev/bcache0 has been created. However, if I try to mount it: >> >> mount -t bcache /dev/bcache0 /mnt >> >> it says: >> >> mount: No such file or directory >> >> with a return code of 32, which is documented as "mount failure". >> >> At this point I reach the limit of my current understanding, but >> would >> like to understand more. > > The intended mount path for multi device filesystems is currently > broken... > Chris got it working (to my surprise) by - I belive - registering all > the > devices via /sys/fs/bcache/register, and then mounting just one of > the block > devices - Chris, is that correct? That is indeed correct. Once the volume has all its components registered, it can be mounted by any of the block devices.