On Sat, Nov 9, 2013 at 3:46 PM, Karanbir Singh <mail-lists@karan.org> wrote:
[...]
 
I can get a bunch of VM's online to trial some of these things, but they
will need to be in one play-cloud or something such, does anyone haves
ideas on how one might create 'real world network problems' on a bunch
of VM's ? eg. how do we cap say 25% of the network interfaces to 10mbps,
and how might we generate latency ? I have a bunch of ideas on howto do
this between machines, but not so much on VMs running on the same ( or
just a few ) machines.

- KB
--
Karanbir Singh
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Bandwidth limiting could probably be accomplished using 'tc', otherwise the "bwlimit" option to rsync might work well enough for a simulation.  Looks like 'tc' can help with latency too (http://stackoverflow.com/questions/614795/simulate-delayed-and-dropped-packets-on-linux).

What kind of control do you have over the mirrors?  One option is to reduce the amount of data that needs to be transferred.  This could be accomplished by:
a) Transferring only package files to mirrors, then running scripts to build the ISOs in place
or
b) Transferring only the ISOs, mounting them through loopback, then building the repos with symlinks into the mounted ISOs.

I am assuming that the packages in the repos are identical to those on the ISOs, so there's already a bunch of duplicate data getting sent over.


❧ Brian Mathis