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Date: Mon, 6 Dec 2010 13:07:54 +0200
From: Gareth de Vaux <bsd@lordcow.org>
To: stable@freebsd.org
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References: <20101127132249.GA80611@lordcow.org>
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Subject: Re: ZFS raidz recovery
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On Sat 2010-11-27 (15:22), Gareth de Vaux wrote:
> Hi all, I'm trying to simulate a disk fail and replacement in
> a raidz array and failing myself. What'm I doing wrong? Here's

Ok I did some science, it looks like the array doesn't like me
throwing zeros at the disk when it's 'offline'. If I take the
disk offline, just fiddle with the array's data, then set the
disk online it resilvers fine.

'zpool replace' also only works if you physically swap out a disk
at the same port, or replace disk1 with disk2 online. 'zpool remove'
and 'zpool detach' don't remove devices from a raidz.

So I can recover an array if I have an extra disk to play with,
to use temporarily or to swap out with. If I don't and a disk is
giving trouble I can't drop it from the array, try to do something
with it, and reinsert it.