zfs discuss - Dec 2009 - Why would some disks in a raidz use partitions and others not?

I have a raidz1 that I have been trying to recover. I am missing one disk due to
catastrophic mechanical failure, but the other disks are fully functional. The
problem is that I cannot import the zpool, despite all the disks being present.
Even with -f, zfs recovery mode set in the kernel options, etc.

The problem is that ZFS thinks devices are constantly missing, when they are
not.

The confusing part is that some of the disks have the ZFS data directly on the
disk, and others are formatted with the ZFS data on a partition of the disk. In
those cases, the partition is essentially the size of the full disk.

I have even manually read through the start of each disk to view the actual
partition map. Some of the disks are partitioned, while others are not.

I cannot figure out how this would have happened, but I am wondering if
it''s something that could have been caused by a BIOS problem on the
system that built the zpool. That system is not available to me, however. I do
not know the exact history of this zpool, but I know it was created by a basic
user and there''s no way that he would have intentionally

Does anybody have any ideas here on how I could recover this zpool?

-Galen

Can you post a "zpool import -f" for us to see?

One thing I ran into recently is that if the drives arrangement was changed
(like drives swapped) it can''t recover.  I moved an 8 drive array
recently, and didn''t worry about the order of the drives.  It could not
be mounted without reordering the drives the same as they were in the original
system.

You can use zdb -l on each drive to see where they used to be.  Which then
allows you to swap out drives until you have it matching again.
-- 
This message posted from opensolaris.org

I am on different hardware, thus I cannot restore the drive configuration
exactly.

I have been able to shuffle and re-import disks in the past with different
zpools, even without an export. Does anybody have more experience with what
scenarios cause a failure to import with the disks being re-ordered?

-Galen

On Dec 22, 2009, at 12:40 PM, James Risner wrote:
> Can you post a "zpool import -f" for us to see?
> 
> One thing I ran into recently is that if the drives arrangement was changed
(like drives swapped) it can''t recover.  I moved an 8 drive array
recently, and didn''t worry about the order of the drives.  It could not
be mounted without reordering the drives the same as they were in the original
system.
> 
> You can use zdb -l on each drive to see where they used to be.  Which then
allows you to swap out drives until you have it matching again.
> -- 
> This message posted from opensolaris.org
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> zfs-discuss mailing list
> zfs-discuss at opensolaris.org
> http://mail.opensolaris.org/mailman/listinfo/zfs-discuss

galenz:  "I am on different hardware, thus I cannot restore the drive
configuration exactly."

Actually, you can learn most of it, if not all of it you need.

Do "zpool import -f" with no pool name and it should dump the issue
with the pool (what is making it fail.)  If that doesn''t contain
privileged info post it here.

The make a table, and run zdb -l on every disk (like zdb -l /dev/c8t1d0) to
record the guid of the device and look at the vdev info to determine which
"/dev/" file had that device.  With that info, you can put the disks
back in the original order (provided you have the same controller hardware.) 
Even if you don''t have the same controller hardware, making a directory
of symbolic links ("ln -s") to the current devices as the old device
names and using "-d /tmp/dir" to import will have it use the old
names.

I''d also be interested from other parties, as to why shuffling them
back into proper order is required.  As I understood, that was a feature of zfs
but it certainly didn''t work for me.
-- 
This message posted from opensolaris.org

On Dec 22, 2009, at 12:48 PM, Galen wrote:
> I am on different hardware, thus I cannot restore the drive  
> configuration exactly.
>
> I have been able to shuffle and re-import disks in the past with  
> different zpools, even without an export. Does anybody have more  
> experience with what scenarios cause a failure to import with the  
> disks being re-ordered?
The order does not matter.  I''m not sure what James is talking about  
here, but
I can assure you that something else is the problem -- thousands of  
imports have
been made with re-ordered disks and there are even YouTube videos  
which show
this feature.

Please provide more detail, including the output of the zpool import  
commands
you have attempted.
  -- richard