From mboxrd@z Thu Jan 1 00:00:00 1970 From: Matthias Ferdinand Subject: Re: /dev/bcache* missing after reboot Date: Thu, 5 Dec 2013 16:37:49 +0100 Message-ID: <20131205153749.GA1848@teapot> References: <9FA7630E-7DC4-4F45-B5E1-FFFB511EFA8B@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Return-path: Received: from sw.mfedv.net ([212.82.36.162]:41222 "EHLO sw.mfedv.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751545Ab3LEPh5 (ORCPT ); Thu, 5 Dec 2013 10:37:57 -0500 Content-Disposition: inline In-Reply-To: <9FA7630E-7DC4-4F45-B5E1-FFFB511EFA8B@gmail.com> Sender: linux-bcache-owner@vger.kernel.org List-Id: linux-bcache@vger.kernel.org To: Thierry De Leeuw Cc: linux-bcache@vger.kernel.org [already sent 2 days ago, but did not appear on the list] On Mon, Dec 02, 2013 at 11:36:47PM +0100, Thierry De Leeuw wrote: > Hi, > > Running Linux 3.12.1. I have disk /dev/sda2 with LVM that has, amongst > other, lvHome as a bcache device, and the cache resides on /dev/sdb1 > > My PC hung and I had to do a forced shutdown. > > Now the /dev/bcache0 (and so on) do not appear anymore. Perhaps you need to re-register / re-attach the backing device to the caching device, something like echo /dev/dm-xx > /sys/fs/bcache/register echo yyyyyyy > /sys/devices/virtual/block/dm-xx/bcache/attach If that does not help, you can try to force starting the bcache backing device without the caching device (might give you serious fs damage with writeback): echo "1" > /sys/devices/virtual/block/dm-xx/bcache/running But since you are using LVM, you might want to create a snapshot of the backing device LV before doing this, just in case. Regards Matthias