Quote Originally Posted by fergus
.....the DVD sometimes fails to boot on my work machine (maybe 2/10 of occasions) whereas it always boots successfully at home (being the machine on which the DVD was created, as it happens). I think the engineering tolerances are so fine because of the amount squeezed into the DVD, that the reader simply fails sometimes. I think it's this kind of failure that causes some users to throw their arms into the air, panic and revert.....
DVDs can hold a lot of data, even the single layer ones that you would use for Knoppix. (Clearly this is not an issue about how much Knoppix packs on specifically, as it packs the data at the same density as any other program would, even if you wrote Puppy Linux to a DVD the spiral would be the same spacing it is with Knoppix). Yea, there do seem to be a lot of slight tolerance issues. These are inflated greatly by doing a burn at high speed. DVD media is also am issue, I have some media that gives me a lot of bad burns when I do everything correct and burn at low speed, other brands that give me much better results. Brand name or paying a lot is no assurance of media quality. I do all of my DVD burns at 4x. Yea, i could do them faster at higher speeds, all of my burners (except maybe the one in my notebook) are rated a lot faster, and all of my media is rated at at least 8x, but doing so leads to problems. Unfortunately, while I have found that the slower I do a CD burn the better quality it is, I have seen some issues on DVD burns when I go at speeds below 4x, so for me all DVD burns (on non-rewritable media) are done at 4x). If you burned at a faster speed I suggest that you try burning another disc at low speed and see if it doesn't boot more reliably on your work system. Other things to try are different media and even burning the DVD at low speed at work. There are some problems booting the Knoppix DVD that seem to be BIOS related, which are understandably extremely frustrating for new users, but your problem does indeed seem to be one of micro tolerances or even dust or oil on optics, and there is a good chance that you could resolve it, particularly if your original burn was at a speed greater than 4x.