zfs discuss - Aug 2011 - Kernel panic on zpool import. 200G of data inaccessible! assertion failed: zvol_get_stats(os, nv) == 0

System: snv_151a 64 bit on Intel.
Error: panic[cpu0] assertion failed: zvol_get_stats(os, nv) == 0,
file: ../../common/fs/zfs/zfs_ioctl.c, line: 1815

Failure first seen on Solaris 10, update 8

History:

I recently received two 320G drives and realized from reading this list it
would have been better if I would have done the install on the small drives
but I didn''t have them at the time. I added the two 320G drives and
created
tank mirror.

I moved some data from other sources to the tank and then decided to go
ahead and do a new install. In preparation for that I moved all the data I
wanted to save onto the rpool mirror and then installed Solaris 10 update 8
again on the 320G drives.

When my system rebooted after the installation, I saw for some reason it
used my tank pool as root. I realize now since it was originally a root pool
and had boot blocks this didn''t help. Anyway I shut down, changed the
boot
order and then booted into my system. It paniced when trying to access the
tank and instantly rebooted. I had to go through this several times until I
caught a glimpse of one of the first messages:

assertion failed: zvol_get_stats(os, nv)

Here is what my system looks like when I boot into failsafe mode.

# zpool import
pool: rpool
id: 16453600103421700325
state: ONLINE
action: The pool can be imported using its name or numeric identifier.
config:

rpool ONLINE
mirror ONLINE
c0t2d0s0 ONLINE
c0t3d0s0 ONLINE

pool: tank
id: 12861119534757646169
state: ONLINE
action: The pool can be imported using its name or numeric identifier.
config:

tank ONLINE
mirror ONLINE
c0t0d0s0 ONLINE
c0t1d0s0 ONLINE

# zpool import tank
cannot import ''tank'': pool may be in use from other system
use ''-f'' to import anyway

I
 installed Solaris 11 Express USB via Hiroshi-san''s Windows tool. 
Unfortunately it also 

panics trying to import the pool although zpool 
import shows the pool online with no errors 

just like in the above doc.

http://imageshack.us/photo/my-images/13/zfsimportfail.jpg/

and here is an eerily identical photo capture made by somebody with a
similar/identical

error. http://prestonconnors.com/zvol_get_stats.jpg

At first I thought it was a copy of my screenshot but I see his terminal is
white and mine is black.

Looks
 like the problem has been around since 2009 although my problem is with
 a newly created 

mirror pool that had plenty of space available (200G in use out of about 500G)
and no snapshots

were taken.

Similar discussion with discouraging lack of follow up:
http://opensolaris.org/jive/message.jspa?messageID=376366

Looks like the defect, it''s closed and I see no resolution.

https://defect.opensolaris.org/bz/show_bug.cgi?id=5682

I have about 200G of data on the tank pool, about 100G or so I don''t
have
anywhere else. I created this pool specifically to make a "safe place"
to
store data that I had accumulated over several years and didn''t have
organized
 yet. I can''t believe such a serious bug has been around for two years
and hasn''t been fixed. Can somebody please help me get this data back?

Thank you.

Jim 


I joined the forums but I didn''t see my post on zfs-discuss mailing
list which
seems alot more active than the forum. Sorry if this is a duplicate for people
on the mailing list.