On Sat, Jun 11, 2011 at 12:36 AM, Ray Morris <support@bettercgi.com> wrote:

Would it be good to be able to serve the same number of users
while reducing resource consumption, including bandwidth, by 70%?

Let's get rid of some of the noise in the data and compare just
DVD versus CD. Using the NetNITCO data let's look at only the
most rcent release, 5.6, and for less noise let's look at
the most popular CPU, i386:


65 /5.6/isos/i386/CentOS-5.6-i386-bin-DVD.iso
25 /5.6/isos/i386/CentOS-5.6-i386-bin-1of7.iso
20 /5.6/isos/i386/CentOS-5.6-i386-netinstall.iso
16 /5.6/isos/i386/CentOS-5.6-i386-bin-5of7.iso
13 /5.6/isos/i386/CentOS-5.6-i386-bin-4of7.iso
13 /5.6/isos/i386/CentOS-5.6-i386-bin-2of7.iso
12 /5.6/isos/i386/CentOS-5.6-i386-bin-3of7.iso
9 /5.6/isos/i386/CentOS-5.6-i386-bin-7of7.iso
9 /5.6/isos/i386/CentOS-5.6-i386-bin-6of7.iso
5 /5.6/isos/i386/CentOS-5.6-i386-LiveCD.iso

CD 1 is downloaded 38% percent as often as the DVD -
a significant amount. So people seem to want CDs a good
portion of the time. Also interesting is that CD 6 and 7
are downloaded about 1/3rd as much as CD 1. It looks like
a lot of people are like me in that they do installations
with only the first CD or two and don't need to download
all 4 GB.

That's a 70% reduction in bandwidth, time, disk io on the
mirrors when they get CD #1 & #2 instead of the full DVD.
Every user who is served by downloading only 2 CDs totalling
1.2 GB instead of 4 GB is good for the mirrors, good for
the network, and good for the users. If they are forced to
download the DVD instead, that means they use three times
the resources that they currently do.

I don't currently run a mirror because I don't have quite
enough bandwidth available, but if I were running a mirror
I'd rather serve up 1.2 GB to each of those users than 4 GB.
--
Ray Morris
support@bettercgi.com