unsupported feature: com.delfix and can't find pool by guid after old STABLE10.0-to-RELENG10.0 upgrade

[Zeus Panchenko]

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greetings,

please help me to understand what am I missing ...

I "successfully" (built/installed world/kernel without errors) upgraded
long time, fine worked root-on-zfs box from 10.0 STABLE (last built in july)
to RELENG 10.0, p11

but after reboot, loader complained on unsupported feature:
com.delfix:hole_birth and com.delfix:embedded_data

when I LiveCD'ed from 10.0 RELEASE image, zpool complained with not all
features supported, so I LiveCD'ed from the image 10.1

I was able to see and import (altroot) my zpool after what I performed
`gpart bootcode ...' (as it was advised in similar cases I was able to
google out) but it didn't help ... after that loader complains with:

ZFS: can't find pool by guid

though value of vfs.zfs.boot.primary_pool is correct and contains the
very guid of my pool ...

and in addition:

lszfs recognizes no pool
lsdev shows no zfs device 

here, please find IPMI console screenshots (I was unable to find how to
grab text):
https://www.dropbox.com/sh/khou69n4wgadxy2/AAC9Q7sbLSPCEdB2CzQvmoGLa?dl=0

in /boot/loader.conf it is set
zfs_load="YES"

and in /etc/rc.conf it is set
zfs_enable="YES"

system was working in production long time before that

So, is there any way to fix that and what is it at all? Is it because of switching from
stable to releng?  I'm giving up in attempts to revive it ...

- -- 
Zeus V. Panchenko				jid:zeus at im.ibs.dn.ua
IT Dpt., I.B.S. LLC					  GMT+2 (EET)
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