--- On Tue, 21/4/09, Andre Robatino <andre(a)bwh.harvard.edu> wrote:
From: Andre Robatino <andre(a)bwh.harvard.edu>
Subject: Re: Can we have a Delta-DVD release
To: fedora-devel-list(a)redhat.com
Date: Tuesday, 21 April, 2009, 9:05 PM
> So there is! Doesn't work on F9
-> F10 but on F10 -> F11 beta DVD (x86_64)
> I get a delta iso image of 2.2GB, about 53% less than
the full iso.
> Hmm, not as good as I was expecting, probably not
worth making a fuss > about unless we could get <1GB.
A lot of people would probably be very happy with cutting
the download in half. On a 768 Kbit/s connection it
would reduce download time from about 12 hours to six.
If the tool doesn't take too long to do the reconstruction
after downloading, and if it's reliable (so one doesn't have
to download 2GB only to find out it doesn't work, then
download the full 4GB anyway) the deltaiso should be
available as a download option.
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The bad news is the reconstruction is quite slow, ~40 mins on a 2GHz Core 2 Duo, 2GB ram.
Here are the full stats, for the delta between F10 final and F11 beta DVD x86_64:
ls -lh Fedora-11-Beta-x86_64-DVD.iso
-rw-rw-r-- 1 user user 4.1G 2009-04-21 17:25 Fedora-11-Beta-x86_64-DVD.iso
makedelta iso Fedora-10-x86_64-DVD.iso Fedora-11-Beta-x86_64-DVD.iso F10_F11_delta.iso
ls -lh F10_F11_delta.iso
-rw-rw-r-- 1 user user 2.2G 2009-04-21 19:33 F10_F11_delta.iso
(53% of the size of the full F11 dvd)
time applydeltaiso Fedora-10-x86_64-DVD.iso F10_F11_delta.iso F11_reconstructed.iso
...
iso sucessfully re-created, md5sum: 9dc917523132a3d269c59c91b647525a
real 41m8.534s
user 37m53.129s
sys 0m34.155s
ls -lh F11_reconstructed.iso
-rw-rw-r-- 1 user user 4.1G 2009-04-21 22:45 F11_reconstructed.iso
md5sum Fedora-11-Beta-x86_64-DVD.iso
9dc917523132a3d269c59c91b647525a
So, the delta iso image is ~half the size of the full iso, and it takes ~40 mins to
reconstruct the full iso (on a 2GHz core2 Duo, 2GB Ram).
Now a question for anyone: does the F11 beta release contain lots of debug code and if so
would you expect the final dvd to have a smaller delta iso?
And one further point: wouldn't this be particularly useful for successive test
releases, alphas, beta, release-candidates, since the deltas would be tiny.