AW: AW: AW: AW: ZFS: Corrupted pool metadata after adding vdev to a pool - no opportunity to rescue data from healthy vdevs? Remove a vdev? Rewrite metadata?

[Thomas Göllner (Newsletter)]

>>> Try reading Max Bruning's blog at http://mbruning.blogspot.com/, there's a good data walk on raidz and raidz on-disk format.
>>
>> I'll do that, thanks for pointing me to it.

Ok... I did read some of it. And I understand so much that I see, that what I want is possible, but far beyond my skills.

>>>> I also think there is no way to write new or edit the lables of the discs?
>>>
>>> This idea is called Block Pointer Rewrite and is not implemented yet. I have found no code to do that.
>>
>> I thought it may come to this -.- Because during my last reading I had to learn, that I have to find the "root block pointer" to recover the maybe overwritten labels... As it changes place and content with each copy on write process (each txg?) it will be a search for the needle in the haystack...
>
> Not at all, what are you referring to is MOS and the one is contained in each UberBlock.

So as this thing is so far beyond my skills, I am sad to point out that I have to give up here. Without someone who will take me by the hand and say what to do step by step I think recovering/rewriting the right labels of my discs is something I will not be able to do within one year or so. It's a pity that ZFS still has no tools for recovering metadata built in. This would be a task to think of in future.

Thanks again for your help Volodymyr. It is a bit of consolation that at least I know now that I have done everything I could.