> -------- Original Message -------- > Subject: dvd+rw-format -force problem > Date: Thu, 31 Jul 2003 21:30:00 +0200 > From: Melvyn Sopacua <freebsd-stable@webteckies.org> > Organization: WebTeckies.org > To: stable@freebsd.org > > I haven't felt the need to fully blank a DVD+RW for a while untill today.Formally speaking blanking is not appicable to DVD+RW. dvd+rw-format -force merely zeros bitmap which describes which ECC blocks were de-iced/written to and nullifies few blocks in the beginning of the media. It's not what one would normally consider as [full] blanking. If you want to nullify the media, e.g. for privacy reasons, 'dvd+rw-format -force /dev/cd0c' won't do the tick, 'growisofs -Z /dev/cd0c=/dev/zero' would.> The problem is the following: > When issuing: > dvd+rw-format -force /dev/cd0c > > it fails, with 'unable to unmount' error.I see the problem now. Fortunately I'm preparing new update addressing performance problems with Pioneer DVR-x06 and will incorporate proper solution even for this problem:-)> A little tracing in the source, shows that the following patch, will work -The proposed solution is not appropriate from security viewpoint, but as already mentioned, proper solution will be provided in the upcoming update, which will be released shortly. Meanwhile just write over the old recording in exact same way it was originally performed, namely with 'growisofs -Z /dev/cd0c ...'.> Can anybody tell wether the author's expectation is wrong,Yes, my expectations were wrong, it's a bug and well be fixed. Cheers. A.
>>>>> "Andy" == Andy Polyakov <appro@fy.chalmers.se> writes:>> I haven't felt the need to fully blank a DVD+RW for a while untill >> today.Andy> Formally speaking blanking is not appicable to Andy> DVD+RW. dvd+rw-format -force merely zeros bitmap which describes Andy> which ECC blocks were de-iced/written to and nullifies few Andy> blocks in the beginning of the media. It's not what one would Andy> normally consider as [full] blanking. If you want to nullify the Andy> media, e.g. for privacy reasons, 'dvd+rw-format -force Andy> /dev/cd0c' won't do the tick, 'growisofs -Z /dev/cd0c=/dev/zero' Andy> would. I don't know how other people's experiences have been, but my drive hasn't been doing well with DVD+RW media. I have the Dell D800 laptop with Dell's DVD combo drive. It writes CD-R and CD-RW media normally. DVD+R's have also worked well for me. The several DVD+RW's that i've bought, however, have all come out with corrupt data. ... now on one of them, I can actually see a spot that looks blank (unrecorded) in the middle of the recorded area ... it's a circle about 1mm or so in size. ... so this might just be bad media. I've been thinking of trying to return it. ... but I've also been thinking of zeroing the media to see if rewriting to it is more successful afterwards (as rewriting several different data sets hasn't had good effect so far. Dave -- ===========================================================================|David Gilbert, Independent Contractor. | Two things can only be | |Mail: dave@daveg.ca | equal if and only if they | |http://daveg.ca | are precisely opposite. | =========================================================GLO================