Andre Robatino wrote:
Jonathan Steffan wrote:
> James Gallagher wrote:
>> Even if the image size is kept below 4.3GB for a single disk, the
>> delta download would be welcomed by many.
>
> Look into makedeltaiso and applydeltaiso. You end up needing the
> original (previous release/target) and the delta. This is only useful if
> the old ISO is left around and you want to end up with a full ISO on the
> other side. The size of a delta ISO between Fedora releases might be
> larger then expected. It would be interesting to see some data on this
> matter.
One can use a script such as the rawread script at
http://www.troubleshooters.com/linux/coasterless.htm
to read an ISO off an optical disc. So the original ISO(s) can be read
off the original install media, if one has those. Or one can just make
a point of keeping the original ISO(s) on the HD after installing. And
even if the size of the deltaiso was 60% or 70% of the full ISO, it
would still be worthwhile to many.
Although the applydeltaiso man page doesn't document it, for the input
ISO argument you can use /dev/dvd after popping in the old DVD (using
the /media directory name doesn't work), for example
applydeltaiso /dev/dvd Fedora-9_10-i386-DVD.diso Fedora-10-i386-DVD.iso
When I tested this, it took somewhat longer than it did when using the
ISO on the HD (48 minutes instead of 38). Still well worth it. I make
a habit of keeping the old ISO on the HD, though, so if the old disc
breaks or something before the new version of Fedora comes out, I can
just burn a new copy.
If {make,apply}deltaiso are generalized to allow multiple input/output
ISOs (I filed bug #497205 for this), this won't work anymore, since most
people only have one optical drive. But in that case, someone could
create a user interface that allows reading/writing the discs by popping
them in, one at a time.