This is what happens when you are not enough paranoid on bandwidth management and monitoring. Especially when you forget that users are lazy, and ignore that consuming bandwidth downloading 10 packages simultaneously from pkg.sabayon.org (our fallback Entropy mirror, main source of fresh pkgs when slave mirrors are still syncing) can have serious impact on our costs.
So, if you are reading this, and still using pkg.sabayon.org to fetch your Entropy packages, please remove it from the list or lower its priority. So, here is 5TB consumed in less than 25 days, just on pkg.sabayon.org (other subdomains, including www, are running on another server). You can see a drop, on the 25th, the day where I re-enabled some bandwidth limiting.
At the same time, because I’m not stupid, starting from Entropy 1.0_alpha9, we are able to enforce fallback mirrors to have the lowest priority, despite what the user setting is inside repositories.conf 
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Every time you download a package from pkg.sabayon.org, a kitten dies.
I hope not I love cats!!!
So, your server is a Hetzner one as well
What are the prerequisites for being a mirror?
It’s not user laziness: most users have no idea how updating and upgrading works, and simply use the equo commands (or Sulfur) to update and upgrade when it becomes common knowledge that an upgrade exists. Most of them don’t understand how the mirror system works (and don’t even know that /etc/entropy/repositories.conf exists). It does not occur to them that there is an impact when mirrors are syncing, because they do not understand the underlying mechanisms. The terms ‘Lack of knowledge’ or ‘lack of understanding’ would be more appropriate than “laziness”. You have to educate people and put in place protective measures, otherwise this kind of thing is bound to happen.
I don’t think it’s laziness at all. People use the tools as they are presented. If using pkg.sabayon.org is an issue then why is it even listed in the repositories.conf file to begin with. This falls squarely on the developers and their not having the foresight that this would cause trouble.
depends. Depends on the skill level. For skilled people: it’s laziness. For newbies: it’s “I stick with the defaults”. Hence, this: http://gitweb.sabayon.org/?p=entropy.git;a=commit;h=a49c4d54ca02900bb30e89b0f305f922ed804e75
I remember upgrading and finding out that entropy downloads everything from pkg.sabayon.org because my country’s mirror and everything nearby didn’t have the correct package. Cancelled it because of the very slow download speed.
The next day, I retried upgrading once again and it downloads from my country’s mirror as I configured it.
Ouch, no edit button…
My point being, it’s possible that some of the traffic mentioned in the post is caused by other mirrors not entirely synced just yet.