A way to alter ZFS metadata stored on a drive ?

[Volodymyr Kostyrko]

24.08.2010 18:01, DarkSoul wrote:

> I now can't detach/remove/replace the following drive because "no valid
> replicas" or because you "can't replace a replacing drive".
>
> I gather the problem would be solved if I had a drive with the proper
> ZDB information and GUID to fool the pool, but I am clueless as to how
> to generate this information, and it doesn't seem from what the manpage
> says, that zdb allows you to modify this information.

Maybe.

> Either that, or find a way to remove these bogus devices, or have the
> pool "forget" that it must replace a device that does not exist anymore,
> with a device that does not exist anymore.
>
> I would gladly welcome any clue as to how the ZDB metadata work and are
> stored on the disk, as I can't find written specifications short of
> probing the ZFS code itself.
>
> I can provide any information required, such as the first 512K for each
> drive (containing the ZDB copies).
>
> Thanks in advance for any help.

http://hub.opensolaris.org/bin/download/Community+Group+zfs/docs/ondiskformat0822.pdf

If you are familiar with python you can use this one:

http://code.google.com/p/zfs-recover

It's a sample python script that's trying to read ZFS from disk. I going 
to commit nvlists unwinding in two days or so.

-- 
Sphinx of black quartz judge my vow.