From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail02.iobjects.de ([188.40.134.68]:46112 "EHLO mail02.iobjects.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755988AbcIVMor (ORCPT ); Thu, 22 Sep 2016 08:44:47 -0400 Subject: Re: unable to handle kernel paging request - btrfs To: Rich Freeman , Btrfs BTRFS References: From: =?UTF-8?Q?Holger_Hoffst=c3=a4tte?= Message-ID: <57E3D23C.3050905@applied-asynchrony.com> Date: Thu, 22 Sep 2016 14:44:44 +0200 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8 Sender: linux-btrfs-owner@vger.kernel.org List-ID: On 09/22/16 14:18, Rich Freeman wrote: > I have been getting panics consistently after doing a btrfs replace > operation on a raid1 and rebooting. I linked a photo of the panic; I > haven't been able to get a text capture of it. > > https://ibin.co/2vx0HhDeViu3.jpg > > I'm getting this error on the latest 4.4, 4.1, and even on an old > 3.18.26 kernel I had lying around. What happens when you try to boot e.g. SystemRescueCD? If it is what I think it is (see below) then that should start bombing as well. > I'm able to boot into single-user mode and if I don't start any > processes the system seems fairly stable. I am also able to start a > btrfs balance and run that for several hours without issue. If I > start launching services the system will tend to panic, though how > many processes I can launch will vary. I don't think that it is a > particular file being accessed that is triggering the issue since the > point where it fails varies. I suspect it may be load-related. If the SystemRescue method does not work then you have either an overheating/dying CPU or - more likely - bad memory. Another - probably unlikely, but not impossible - option would be to delete the swap file, if you have one. I've seen some super-strange things with corrupt or incorrectly created swap *even if it isn't heavily used*, right after boot. E.g. if your swapfile was fallocated instead of dd'ed and lives on ext4 or XFS, you *must* use the -z option to pre-touch all extents. Or maybe it's the ghost of ZFS, if that's patched in as well.. :-) -h