Show Posts
1
Users / Re: Status of the LinuxMCE DVD's
« on: September 10, 2007, 07:20:38 pm »
From our "I don't really know what I'm talking about, but here goes" department ....
I was under the impression that CDs and DVDs had some redundancy in the recorded data. So, you can get some scratches on the surface making some sectors unreadable, but the data can still be recovered from bits stashed around in different sectors. With a lot of scratches (or if you're really unlucky) some data will be completely lost. If you have a data CD or DVD that is having read problems, you'll hear the drive heads moving violently about. I think it's seeking to the alternate sectors to reconstruct the data from the lost sector.
My suspicion is that the more complete version of what this vendor is telling you is: "All glass masters have flaws, but luckily the redundancy still allows you to read 100% of the original data. For a particular chunk of data to be completely unrecoverable (and look like 000's), the glass master must have *a lot* of flaws." I further suspect that the plants which guarantee 100% readability are also counting on the disks being readable when the redundancy is taken into account. They probably also see flaws in the glass masters but test 100% readability and toss the glass master if it doesn't pass. A passing glass master might still contain flaws, but the data is 100% readable.
The net effect is the same, of course. Thanks for your efforts and no problem about the delays.
I was under the impression that CDs and DVDs had some redundancy in the recorded data. So, you can get some scratches on the surface making some sectors unreadable, but the data can still be recovered from bits stashed around in different sectors. With a lot of scratches (or if you're really unlucky) some data will be completely lost. If you have a data CD or DVD that is having read problems, you'll hear the drive heads moving violently about. I think it's seeking to the alternate sectors to reconstruct the data from the lost sector.
My suspicion is that the more complete version of what this vendor is telling you is: "All glass masters have flaws, but luckily the redundancy still allows you to read 100% of the original data. For a particular chunk of data to be completely unrecoverable (and look like 000's), the glass master must have *a lot* of flaws." I further suspect that the plants which guarantee 100% readability are also counting on the disks being readable when the redundancy is taken into account. They probably also see flaws in the glass masters but test 100% readability and toss the glass master if it doesn't pass. A passing glass master might still contain flaws, but the data is 100% readable.
The net effect is the same, of course. Thanks for your efforts and no problem about the delays.