I have just burnt a backup of a Video DVD on a DVD+R DL. After burning I made a few big scratches on the disc, because I dont have very much experience w/ Dual Layer disks.
I still can play the DVD, but I don't think that I can searcht the whole movie to check if the DVD is still good.
So I made a scan w/ kprobe 2.5.2, which can be seen in the attachement.
The scatch seemed only to influence the first layer, which I believe ist the one which ist closer to the surface of the disc. But the program found 5 errors in a small section at about 30% of the first layer and also in this section the PIF is about as high as the PI at 93.
I think, that the bad overall results on the second layer are normal, because they are not influenced by the positions of the scratches.
Edit: I now also made a speedtest, because in a different forum they someone said I should do this, but on a different drive, because it doesn't work w/ this drive and my Nero version.
The result looks like the ones I founr w/ google four duoble layer disks, except the small kink in the middle.
But maybe this is because it is a slimline notebook drive, which has only a max. read speed of 6x for DVD+R DL. I haven't found any results fpor drives of this kind.
Also I don' think that the kink comes from a scratch, because I don't have the big scratches so far on the outside.