From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-ie0-f180.google.com ([209.85.223.180]:38031 "EHLO mail-ie0-f180.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752454Ab3GNNyS (ORCPT ); Sun, 14 Jul 2013 09:54:18 -0400 Received: by mail-ie0-f180.google.com with SMTP id f4so23553938iea.39 for ; Sun, 14 Jul 2013 06:54:17 -0700 (PDT) MIME-Version: 1.0 In-Reply-To: <20130714134926.GC29644@carfax.org.uk> References: <20130714134926.GC29644@carfax.org.uk> From: Dave Barnum Date: Sun, 14 Jul 2013 13:53:57 +0000 Message-ID: Subject: Re: Need help mounting broken btrfs Fedora 19 To: Hugo Mills , Dave Barnum , linux-btrfs@vger.kernel.org Content-Type: text/plain; charset=ISO-8859-1 Sender: linux-btrfs-owner@vger.kernel.org List-ID: Thanks for your reply. I have tried -o degraded and recover but I keep getting the error messages above in dmesg such as: btrfs: failed to read chunk root on sdc2 On Sun, Jul 14, 2013 at 1:49 PM, Hugo Mills wrote: > On Sun, Jul 14, 2013 at 01:43:41PM +0000, Dave Barnum wrote: >> I need some help as may have lost some number of files on a btrfs raid >> 1 volume. I'm not quite sure what happend which, I know, only adds to >> the problem. >> >> On my computer #1 I had only a month or so ago installed Fedora 19 >> Beta and at the time of install chose BTRFS, raid 1. Recently one of >> the drives started complaining that it was going to die. WIthout >> taking it out of the array (perhaps I should have done that) I turned >> off the system and swapped the drive with another. From then on I lost >> my ability to boot the system. I could not get anything to work with >> the new hard drive. Then I put the old hard drive back in so that I >> could try to boot again. Still nothing. At one point I think I was >> able to see grub - but at this point, I'm not. I just get boot disk >> failure. > > Try adding the option "degraded" to your mount options. With grub, > this should be possible to do manually at boot time. That should get > yout the ability to mount the FS with just a single mirror. If that > works, you can then use btrfs dev add to add the new device to the > filesystem, and then a full balance to recreate the mirror. > > Hugo. > >> Further more on the failing drive, drive A, I can still see the >> patitions but I cannot mount it on another system. On drive B (the >> other half of the mirror) I do not see any partitions. I tried copying >> the partition structure using sfdisk from A to B but that probably was >> not smart. >> >> I plugged drive A into computer #2 using a live Fedora and Ubuntu CD >> to try to mount the volume. However in both distributions I am unable >> to mount the volume. I've tried mounting using -o degraded but I still >> get the same error. The error I'm seeing when I try to mount the >> filesystem goes like this: >> >> Quote: >> [10792.307425] device label fedora_ison devid 2 transid 48720 /dev/sdc2 >> [10792.308202] btrfs: allowing degraded mounts >> [10792.308206] btrfs: disk space caching is enabled >> [10792.308599] btrfs: failed to read chunk root on sdc2 >> [10792.308799] btrfs warning page private not zero on page 20979712 >> [10792.320146] btrfs: open_ctree failed >> >> I believe the superblock may be in tact since when i turn the command >> ./btrfs-show-super /dev/sdc2 I get: >> >> Quote: >> root@ubuntu:/downloads/btrfs-progs# ./btrfs-show-super /dev/sdc2 >> superblock: bytenr=65536, device=/dev/sdc2 >> --------------------------------------------------------- >> csum 0xfc19c468 [match] >> bytenr 65536 >> flags 0x1 >> magic _BHRfS_M [match] >> fsid cbbf7d4c-f7a0-43ff-aed5-77b347d6ff25 >> label fedora_ison >> generation 48720 >> root 1105526784 >> sys_array_size 226 >> chunk_root_generation 46504 >> root_level 1 >> chunk_root 20979712 >> chunk_root_level 1 >> log_root 0 >> log_root_transid 0 >> log_root_level 0 >> total_bytes 2988521291776 >> bytes_used 598216536064 >> sectorsize 4096 >> nodesize 4096 >> leafsize 4096 >> stripesize 4096 >> root_dir 6 >> num_devices 2 >> compat_flags 0x0 >> compat_ro_flags 0x0 >> incompat_flags 0x1 >> csum_type 0 >> csum_size 4 >> cache_generation 48720 >> dev_item.uuid 5f61edaa-7f12-4ec5-a024-02f7797e1400 >> dev_item.fsid cbbf7d4c-f7a0-43ff-aed5-77b347d6ff25 [match] >> dev_item.type 0 >> dev_item.total_bytes 1494260645888 >> dev_item.bytes_used 482110078976 >> dev_item.io_align 4096 >> dev_item.io_width 4096 >> dev_item.sector_size 4096 >> dev_item.devid 2 >> dev_item.dev_group 0 >> dev_item.seek_speed 0 >> dev_item.bandwidth 0 >> dev_item.generation 0 >> >> Could someone help me troubleshoot why I can't mount my volume? I >> would REALLY appreciate it! Perhaps there is a way to repair my broken >> tree structure? >> >> Thank You! > > -- > === Hugo Mills: hugo@... carfax.org.uk | darksatanic.net | lug.org.uk === > PGP key: 65E74AC0 from wwwkeys.eu.pgp.net or http://www.carfax.org.uk > --- ... one ping(1) to rule them all, and in the --- > darkness bind(2) them.