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Date: Fri, 13 Oct 2006 03:47:53 -0400
From: James Snow <snow@teardrop.org>
To: Andrew - Supernews <andrew@supernews.net>
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Cc: ade@freebsd.org, freebsd-geom@freebsd.org
Subject: Re: gmirror panics on startup, and some other cases
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On Thu, Jul 20, 2006 at 03:00:52AM +0100, Andrew - Supernews wrote:
> Running RELENG_6 as of June 21 2006, we ran into what looks like a
> couple of related gmirror bugs relating to synchronization problems
> during destruction. In the worst case these can cause a kernel panic
> before reaching single-user mode, if geom_mirror is loaded from
> loader.conf.

I recently encountered this same problem, also in RELENG_6.  

My disk was a removable one, so attaching it to the system would bring
the system down when gmirror tasted the disk.  Since all I really wanted
was to mount the underlying filesystems to copy data off the disk, I
found myself wanting for a way to tell gmirror to simply not taste the
disk when it was inserted.

I worked around my problem and got my data, but I still wondered: Is
there a way to tell gmirror or geom to completely ignore a particular
disk?  If I could have done that, presumably I could have written new
gmirror labels to this disk - overwriting the corrupted ones - and gone
on my merry way.


-Snow