On Mon, 1 Jun 2009, Chris Adams wrote:
Once upon a time, Michael Cronenworth mike@cchtml.com said:
Sounds like the mirrors should use bitorrent? (then why not just let users use bittorrent) This will be my last random thought today.
Bittorrent is not some magic wand. The problem is just the volume of bits that would have to be pushed out in a short period of time to be useful. To generate 25G+ of data and try to distribute it in a timely fashion, Red Hat would have to dedicate large amounts of bandwidth for just that purpose. The bits would have to get from the point the ISOs are generated to the public servers to at least some consumers (be they mirrors or end-users).
Let's say you wanted to get 25G out (at least to the initial point of distribution) in 4 hours. That's an average line rate of about 14 megabits per second to distribute them to _one_ other site. If you have just 10 other sites trying to get them simultaneously, you'll need a full OC-3 or a fractional gigabit ethernet link.
Also, mirrors aren't going to use Bittorrent to fetch bits because AFAIK the automation is not available. I have scripts wrapped around rsync to keep things in sync (and even that still needs some "hand holding" now and then).
And it is probably worth reading the analysis of mirrors and torrents written by John Hawley
http://linuxsymposium.org/2008/ols-2008-Proceedings-V1.pdf page 173
-sv