[Date Prev][Date Next] [Thread Prev][Thread Next] [Date Index] [Thread Index]

Re: Dual layer DVD

On Tue, Sep 07, 2004 at 07:04:44PM +0000, Joel Baker wrote:
>The simple answer would be to make sure that we have a reasonable selection
>of two "disks" (for individual burns or dual-sided single-layered press
>runs), and a way to make it easy for folks wanting to burn or press
>single-sided dual-layer discs from those such that it requires no user
>intervention to read the total (I don't know enough about the gritty
>details of bridging filesystems across layers to know what this requires).

Dual-layer discs will need a single large filesystem that is simply
split across the two layers. On data DVDs, the data is normally
written to the lower layer from the inner edge to the outer edge, then
swings back and starts again at the inner edge of the top layer. The
filesystem is contiguous, though - the blocks logically continue
uninterrupted across the layer split. A good plan is to try not to
split a file across the split, purely for performance reasons.

What I'd like us to do is create several image sizes for each arch:

  1 business card image (ISO, maybe jigdo too)

  1 netinst image (ISO, maybe jigdo too)

  13 or 14 650 MB CDs (jigdos on the main cdimage site, with some
  mirrors carrying the full ISOs)

  2 4.7 GB DVDs (ditto)

  1 8.5 GB DL DVD image (probably jigdo only)

Jigdo means that we can do this without eating terabytes of disk space
all over the world. To get the DL DVD images pressed will probably
take extra preparation work - see my new dvdtape package for details.

Steve McIntyre, Cambridge, UK.                                steve@einval.com
"I can't ever sleep on planes ... call it irrational if you like, but I'm
 afraid I'll miss my stop" -- Vivek Dasmohapatra

Attachment: signature.asc
Description: Digital signature

Reply to: