700/703 MB CD size

Steve Langasek steve.langasek at ubuntu.com
Mon Jan 26 07:33:11 GMT 2009

On Sat, Jan 24, 2009 at 03:25:56PM +0000, Paul Sladen wrote:
> On Sat, 24 Jan 2009, Jani Monoses wrote:
> > The current Ubuntu CD image size limit is 700

> It is, as you note (80*60*75*2048 bytes), hopefully plus lead-in and
> lead-out sector allowances and often with a tiny little bit extra (see
> "overburning").

> Where is the comparision being done, is it the number of bytes in the
> resulting ISO (eg. inclusive of meta-data), or the number of bytes of the
> packages, in the hope that the final result (metadata added) will fit?

> One advantage of producing an exactly size .iso might be that people would
> not try to burn it by dragging it *as a file* (rather than image) onto a
> CD-R; the software would complain earlier it wouldn't fit.

> If you're *really* tight of space, there's about half-a-megabyte (N files *
> ~1024) of it spare at the end of unfilled sectors (less on the desktop CD).

Here is the size limit and accompanying comments from the bin/publish-daily

        # http://en.wikipedia.org/wiki/CD-ROM says
        # 737280000; Media Motion say 736051200 for our
        # pressed CDs, so we'll use the smaller value.
        # ... except apparently some software/media has
        # problems with anything over 700 (binary) MB. Argh.
        SIZELIMIT="$((700 * 1024 * 1024))"

This was added by Colin in revision 555.  Colin, do you remember what had
problems with the larger value?

It would certainly be great to suddenly have another 2MB of room to spare on
the CD images...

Steve Langasek                   Give me a lever long enough and a Free OS
Debian Developer                   to set it on, and I can move the world.
Ubuntu Developer                                    http://www.debian.org/
slangasek at ubuntu.com                                     vorlon at debian.org

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