From mboxrd@z Thu Jan 1 00:00:00 1970 From: Marc MERLIN Subject: Disabling bcache from boot when it crashes? Date: Wed, 24 Feb 2016 08:37:16 -0800 Message-ID: <20160224163716.GA19447@merlins.org> References: <20160215060410.GA30802@merlins.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Received: from magic.merlins.org ([209.81.13.136]:59868 "EHLO mail1.merlins.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757577AbcBXQhh (ORCPT ); Wed, 24 Feb 2016 11:37:37 -0500 Content-Disposition: inline In-Reply-To: Sender: linux-bcache-owner@vger.kernel.org List-Id: linux-bcache@vger.kernel.org To: Eric Wheeler Cc: linux-bcache@vger.kernel.org On Wed, Feb 24, 2016 at 06:53:05AM +0000, Eric Wheeler wrote: > Do you have the bcache stability patches? 4.3.3 might be missing some > critical patches. > > Be sure to cherry-pick these from linux 4.5-rc1: > git cherry-pick 2ef9ccbf~1..627ccd20 > or use one of the 4.1 or 3.18 longterm kernels. > > I've not see any memory allocation issues before in bcache, but you > definitely want those patches for general stability. I'm running 4.4.2, so I'm assuming I don't have those fixes, thanks for the heads up. Well, your message is timely, just as you wrote this, I got bcache that crashed my system as I was shutting down, and then I was unable to ever reboot because bcache would detect my partitions, start bcache, and crash before I could do anything to fix it. A few questions though: 1) is there any bcache boot option I can give to disable bcache at boot time? 2) I had to boot from rescue media and sadly the version of wipefs there wasn't good enough to find the bcache sig and remove it. I then tried to change the bcache cache partition type to 0, but that didn't help either. Eventually I had to shrink the bcache cache partition to 1 cylinder and finally then it stopped being detected at boot and the crashes stopped. (dd of /dev/zero would have worked, but it's an ssd, and I didn't want to allocate blocks on the flash that had not been used yet to give more room for garbage collection). Was there a better way of doing this? Thanks, Marc -- "A mouse is a device used to point at the xterm you want to type in" - A.S.R. Microsoft is to operating systems .... .... what McDonalds is to gourmet cooking Home page: http://marc.merlins.org/