Re: Re: btrfs repair and zero-log doesn't seem to do anything

Re: Re: btrfs repair and zero-log doesn't seem to do anything

[Calle Kabo]

> IMHO there will be 2 alternative method to recover:
>
> 1) Btrfs restore
>    The safest method to recover files.
>    Although it may need a lot of space to restore recovered data.
>
> 2) Btrfs check --init-extent-tree
>    This will use fs tree to try to rebuild the extent tree.
>    I don't believe it's only extent tree corrupted, so this may make
>    things even *worse*, but at least it won't take several TBs to
>    recover data which you may already have backup.

Thanks! I tested restoring a small directory and it worked beautifully.
Is there any way to list the files/directories? I don't think I can
remember all of the paths that were on there...

/Calle

Re: btrfs repair and zero-log doesn't seem to do anything

[Qu Wenruo]

At 12/05/2016 11:49 AM, Calle Kabo wrote:
>
>> IMHO there will be 2 alternative method to recover:
>>
>> 1) Btrfs restore
>>    The safest method to recover files.
>>    Although it may need a lot of space to restore recovered data.
>>
>> 2) Btrfs check --init-extent-tree
>>    This will use fs tree to try to rebuild the extent tree.
>>    I don't believe it's only extent tree corrupted, so this may make
>>    things even *worse*, but at least it won't take several TBs to
>>    recover data which you may already have backup.
>
> Thanks! I tested restoring a small directory and it worked beautifully.
> Is there any way to list the files/directories? I don't think I can
> remember all of the paths that were on there...
>
> /Calle

I'm not familiar with btrfs-restore tool.
But a quick glance at the man page shows there is some options like
-r <rooid>
--path-regex <path>
-d
--list-roots
-D

Those options would help.
Maybe -D would list all the file structures?


And if btrfs restore works perfectly fine without even a problem,
then it seems to indicate that only extent tree is corrupted.
In that case, --init-extent-tree may have a little chance to recover the fs.
(But under most case, maybe over 50%?, it may make things worse)

Thanks,
Qu

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Re: btrfs repair and zero-log doesn't seem to do anything

[Calle Kabo]

> Maybe -D would list all the file structures?

I tried that first but didn't see anything, but when combined with -v it
shows the files that would have been restored.

e.g.
# btrfs restore -v -D --path-regex '^/(|Documents(|/.*))$'
/dev/mapper/data-0 /tmp


Awesome, big thanks for your help!

/Calle