Subject: Re: corruption on compression, or bitrot?
To: The Grey Wolf <greywolf@starwolf.com>
From: Eric Haszlakiewicz <erh@nimenees.com>
List: current-users
Date: 10/02/2004 13:23:53
On Thu, Sep 09, 2004 at 05:10:03PM -0700, The Grey Wolf wrote:
> Fine.  Split it into 64MB chunks using dd if=file of=file.$n bs=1024k \
> 	count=64 skip=`expr $n \* 64`.  OK.
> Gzip each separate one using gzip -cv1 $file.$n > $file.$n.gz.  OK.
> As a sanity check, run gzip -dvc $file.$n.gz > /dev/null.  OK.
> Go back at the end of the run and try again.  *BOOM*  First one gets a
> crc error.
> 
> Is this filesystem error, disk error/bitrot or what?  What would cause
> the corruption to occur after the file had already been checked for
> integrity?

	gzip bug perhaps?  There was at least one recently that would insert
a spurious null byte.  Noticed due to file names in certain tar files
getting truncated.
	Then again, if you don't get an error the first time you test the file
it's probably something else.

eric