Re: Need help mounting broken btrfs Fedora 19

[Dave Barnum <dave@thebarnums.com>]

Any other suggestions?

On Mon, Jul 15, 2013 at 6:56 AM, Dave Barnum <dave@thebarnums.com> wrote:
> Thanks Wang,
>
> This was the result:
> root@ubuntu:/downloads/btrfs-progs# ./btrfs chunk-recover /dev/sdc2
> no recoverable chunk
> Recover the chunk tree successfully.
>
> Still unable to mount.
>
> On Sun, Jul 14, 2013 at 2:03 PM, Wang Shilong <wangshilong1991@gmail.com> wrote:
>> Hello,
>>
>> You call pull from:
>>         git://git.kernel.org/pub/scm/linux/kernel/git/mason/btrfs-progs.git
>>
>> Miao implement chunk tree recover function, you can try it with like.
>>         btrfs  chunk-recover /dev
>> Maybe this can help you.
>>
>> Thanks,
>> Wang
>>> 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.
>>>
>>> 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!
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>>