From owner-freebsd-stable@FreeBSD.ORG  Tue Jun  5 15:16:04 2007
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Date: Tue, 5 Jun 2007 17:03:45 +0200
From: Marc "UBM" Bocklet <ubm@u-boot-man.de>
To: freebsd-stable@freebsd.org
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Subject: gmirror on a disk with data already on it
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Hiho! :-)

The gmirror man page says that if gmirror is used on a disk, the last
sector of that disk is overwritten with the metadata gmirror uses.

So what I would like to know is, how risky is it to mirror a disk which
already has data on it?

Is there a chance that I might render my system unbootable?

Is there any way to find out what data that last sector holds?

Thanks in advance! :-)

Bye
Marc