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Date: Tue, 1 Dec 2009 09:53:18 +0100
From: Ruben de Groot <mail25@bzerk.org>
To: James Phillips <anti_spam256@yahoo.ca>
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	James Phillips <anti_spam256@yahoo.ca>,
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Cc: Bruce Cran <bruce@cran.org.uk>, freebsd-questions@freebsd.org
Subject: Re: Phoronix Benchmarks: Waht's wrong with FreeBSD 8.0?
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On Mon, Nov 30, 2009 at 11:34:06PM -0800, James Phillips typed:
> 
> 
> --- On Mon, 11/30/09, Bruce Cran <bruce@cran.org.uk> wrote:
> 
> > 
> > This is actually the way UFS/FFS works too: when my system
> > was crashing
> > fairly regularly I was a bit surprised to find empty files
> > after
> > editing them.
> > 
> > Also, I just verified that saving a file, rebooting,
> > editing it again
> > (with ee(1)) and powering off the system does still result
> > in a zero
> > length file being on disk.
> > 
> 
> Ok, good to know.
> 
> I saw UFS corruption once with frequent restarts, but assumed that was because the "delayed filesystem checking" never had a chance to run.
> 
> Since I don't have a UPS I guess backups are doubly important.

Note that finding an empty file you had just been editing before a 
crash is NOT UFS corruption. It's data loss, probably caused by
softupdates, which guarantees filesystem consistency in the case
of a crash, but it can sometimes be up to a minute behind in 
actually writing the data blocks to the disk.

Ruben