zfs discuss - Aug 2007 - restore lost pool after vtoc re-label

hi all,

i''ve been using a SAN LUN as the sole member of a zpool with one
additional zfs filesystem. this is a flat SAN fabric, so this LUN was available
to other systems on the fabric, and one of them came up with "wrong magic
number" for several drives, and, as best i can tell, the vtoc for my zpool
LUN was over-written on that host via format labeling to correct the error.

all of the data should still be there, nobody else has touched the LUN, but
zpool doesn''t see anything.

is it possible to recover that zpool somehow? i know it exists and the LUN has
been un-touched since the labeling.

thanks in advance.
 
 
This message posted from opensolaris.org

Hello o,

Wednesday, August 15, 2007, 12:17:04 AM, you wrote:

op> hi all,

op> i''ve been using a SAN LUN as the sole member of a zpool with one
op> additional zfs filesystem. this is a flat SAN fabric, so this LUN
op> was available to other systems on the fabric, and one of them came
op> up with "wrong magic number" for several drives, and, as best i
op> can tell, the vtoc for my zpool LUN was over-written on that host
op> via format labeling to correct the error. 

op> all of the data should still be there, nobody else has touched
op> the LUN, but zpool doesn''t see anything. 

op> is it possible to recover that zpool somehow? i know it exists
op> and the LUN has been un-touched since the labeling.


How that LUN was being used by ZFS? I mean did you specify entire LUN
(c0t0d0 - without specifying a slice?) If it''s the case try to
''format
-e disk'' with proer disk, then create EFI label with s0 covering
entire disk (minus that reservation in EFI which you won''t be able to
overwrite anyway I guess). Then try to ''zpool import'' and
check if it
works.

If it''s not the case then you''ll have to recreate whatever
label there
was...



-- 
Best regards,
 Robert Milkowski                           mailto:rmilkowski at task.gda.pl
                                       http://milek.blogspot.com

> Hello o,
> 
> Wednesday, August 15, 2007, 12:17:04 AM, you wrote:
> 
> op> hi all,
> 
> op> i''ve been using a SAN LUN as the sole member of a
> zpool with one
> op> additional zfs filesystem. this is a flat SAN
> fabric, so this LUN
> op> was available to other systems on the fabric, and
> one of them came
> op> up with "wrong magic number" for several drives,
> and, as best i
> op> can tell, the vtoc for my zpool LUN was
> over-written on that host
> op> via format labeling to correct the error. 
> 
> op> all of the data should still be there, nobody
> else has touched
> op> the LUN, but zpool doesn''t see anything. 
> 
> op> is it possible to recover that zpool somehow? i
> know it exists
> op> and the LUN has been un-touched since the
> labeling.
> 
> 
> How that LUN was being used by ZFS? I mean did you
> specify entire LUN
> (c0t0d0 - without specifying a slice?) If it''s the
> case try to ''format
> -e disk'' with proer disk, then create EFI label with
> s0 covering
> entire disk (minus that reservation in EFI which you
> won''t be able to
> overwrite anyway I guess). Then try to ''zpool import''
> and check if it
> works.
> 
> If it''s not the case then you''ll have to recreate
> whatever label there
> was...
> 
> 
> 
> -- 
> Best regards,
> Robert Milkowski
> 
> ailto:rmilkowski at task.gda.pl
> 
> ttp://milek.blogspot.com
> 
> _______________________________________________
> zfs-discuss mailing list
> zfs-discuss at opensolaris.org
> http://mail.opensolaris.org/mailman/listinfo/zfs-discu
> ss
thanks much - that worked perfectly.
 
 
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