From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wi0-f170.google.com ([209.85.212.170]:37834 "EHLO mail-wi0-f170.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753636AbbJNU1g (ORCPT ); Wed, 14 Oct 2015 16:27:36 -0400 Received: by wijq8 with SMTP id q8so99132284wij.0 for ; Wed, 14 Oct 2015 13:27:35 -0700 (PDT) Message-ID: <561EBAB1.6030600@gmail.com> Date: Wed, 14 Oct 2015 22:27:29 +0200 From: Dmitry Katsubo MIME-Version: 1.0 To: Anand Jain CC: linux-btrfs@vger.kernel.org Subject: Re: Recover btrfs volume which can only be mounded in read-only mode References: <561E6969.40500@oracle.com> In-Reply-To: <561E6969.40500@oracle.com> Content-Type: text/plain; charset=UTF-8 Sender: linux-btrfs-owner@vger.kernel.org List-ID: On 14/10/2015 16:40, Anand Jain wrote: >> # mount -o degraded /var >> Oct 11 18:20:15 kernel: BTRFS: too many missing devices, writeable >> mount is not allowed >> >> # mount -o degraded,ro /var >> # btrfs device add /dev/sdd1 /var >> ERROR: error adding the device '/dev/sdd1' - Read-only file system >> >> Now I am stuck: I cannot add device to the volume to satisfy raid >> pre-requisite. > > This is a known issue. Would you be able to test below set of patches > and update us.. > > [PATCH 0/5] Btrfs: Per-chunk degradable check Many thanks for the reply. Unfortunately I have no environment to recompile the kernel, and setting it up will perhaps take a day. Can the latest kernel be pushed to Debian sid? 1. Is there any way to recover btrfs at the moment? Or the easiest I can do is to mount ro, copy all data to another drive, re-create btrfs volume and copy back? 2. How to avoid such a trap in the future? 3. How can I know what version of kernel the patch "Per-chunk degradable check" is targeting? 4. What is the best way to express/vote for new features or suggestions (wikipage "Project_ideas" / bugzilla)? Thanks! -- With best regards, Dmitry