problem booting to multi-vdev root pool

[Andrei Lavreniyuk]

>> Sorry to make you jump through so many hoops.
>> Now that I see that the probed config is entirely correct, the problem appears to
>> be quite obvious: vdev_alloc is not able to properly use spa_version in this
>> context because spa_ubsync is not initialized yet.
>>
>> Let me think about how to fix this.
>
> I hope that the following simple patch should fix the problem:
> http://people.freebsd.org/~avg/spa_import_rootpool.version.diff


  At mount system trap and reboot.


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Best regards, Andrei Lavreniyuk.