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Date: Thu, 29 Nov 2007 12:16:09 -0600
From: "Rick C. Petty" <rick-freebsd@kiwi-computer.com>
To: Bruce Evans <brde@optusnet.com.au>
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Subject: Re: misc/118249: moving a directory changes its mtime
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On Wed, Nov 28, 2007 at 03:34:57PM +1100, Bruce Evans wrote:
> On Mon, 26 Nov 2007, Rick C. Petty wrote:
> 
> >On Mon, Nov 26, 2007 at 07:00:05AM +0000, Bruce Evans wrote:
> >> doing this before successful completion.  My regression tests haven't
> >> reported any failures from them but I think failures can occur for
> >> disk-full and I/O errors and the former is easy to test.
> >
> >Can't you test the latter using gnop?
> 
> Not easily, since I've never hear of gnop.  It's probably easily for me
> to edit the kernel.  I suppose that for i/o errors we would want an error
> quite often but on not more than about 1% of syscalls.  The errors should
> be recoverable by retrying and no utilitites should crash from them :-).

I would think gnop(8) is easier:

truncate -s 10g /usr/tmp/disk.raw
mdconfig -af /usr/tmp/disk.raw
gnop create -f 1 /dev/md0
newfs -U /dev/md0.nop
...

The -f option describes failure rate (simulating I/O errors) in percentage.

-- Rick C. Petty