Re: Fi corruption on RAID1, generation doesn't match

[Qu Wenruo <quwenruo.btrfs@gmx.com>]

On 02/07/2016 10:23 PM, Andreas Hild wrote:
> On 7 February 2016 at 20:56, Qu Wenruo <quwenruo.btrfs@gmx.com> wrote:
>>
>> You are wondering why data is still 168G, but that's the allocated data
>> chunk size.
>>
>> It means 168G space is allocated to store data, but only 42M is used.
>> Matches with your vanilla df output.
>>
>> So it doesn't mean you data are still here.
>
> I understand now. Thanks very much!
>
>
> [...]
>>
>> That's the previous transaction's tree root.
>> If you are in good luck, previous trans may has all your data.
>> But if you are in bad luck, it may already after the remove.
>>
>> Normally, at least something should still be in previous trans.
>>
>> Now use btrfsck to check if previous trans is in good shape.
>>
>> # btrfsck --tree-root 647630028800
>>
>> If btrfsck only reports minor problems, like space cache tree mismatch, then
>> it means previous trans are almost OK.
>>
>> Then let btrfsck to revert to previous trans:
>>
>> # btrfsck --tree-root 647630028800 --repair
>>
>> If you're really in good luck, then you can mount the fs and found something
>> in it.
>
>
> Great! I'll try this.
>
> The 'tree-root' option must be a recent development. My 'stable'
> Debian live disk does not recognize this option.
>
> Could any one recommended a live disk that already includes this btrfsck option?
>
> Many thanks!
>
> Andreas
>
Try latest installation ISO from Archlinux, which should be recent 
enough, if not already latest.

Another recommendation should be latest Fedora, which should be no later 
than Arch.
But with a better LiveCD environment, like with GUI, other than pure CLI 
from Archlinux ISO.

Thanks,
Qu