[CentOS-devel] Getting there faster

On Sat, Nov 9, 2013 at 3:46 PM, Karanbir Singh <mail-lists at 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
> +44-207-0999389 | http://www.karan.org/ | twitter.com/kbsingh
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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
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