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Date: Sun, 6 Jul 2003 09:17:54 -0700
From: Joshua Oreman <oremanj@webserver.get-linux.org>
To: Terry Lambert <tlambert2@mindspring.com>
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cc: hackers@freebsd.org
Subject: Re: recovering data from a truncated vn-file possible?
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On Sun, Jul 06, 2003 at 09:06:23AM -0700 or thereabouts, Terry Lambert wrote:
> Josh Brooks wrote:
> > Long story short, I have a 4gig vn-backed filesystem.  The file backing it
> > is now missing the last 750megs ... I can vnconfig it, but when I fsck it
> > I see:
> 
> Probably the first thing you'll want to do is write a small program
> to open the file and write a zero at the offset of the 750M to make
> the "device" the right size.  Most of the recovery tools, including
> fsck, go into convulsions if the device size shrinks on them.  So the
> first thing you want to do is change the size back to what it should
> be.

He said it used to be 4gigs, so one would have to write a zero at 4gigs.
Or do this (slower, but it works):
$ dd if=/dev/zero bs=1m count=750 >> myfile

-- Josh

> 
> -- Terry
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