Cosmos, Service is Retired
Technology Services retired the Cosmos Linux mirror service on June 1, 2018.
Cosmos was launched in 2005 to provide our campus Linux community with reliable access to security updates. At the time, it was common for publicly-available mirrors to be overloaded by traffic from new releases or critical updates. Bandwidth was limited in most cases and load balancing was cost-prohibitive.
In the 12 years that Cosmos has been in operation, we've seen substantial improvements in available mirror networks as well as capacity boosts to our campus network. We've considered big service changes in response to the changing world (such as eliminating FTP), but ultimately concluded that the value provided by Cosmos is a small fraction of what it once was and that the service's original mission has been fulfilled by improved public mirror networks.
We removed Cosmos from public mirror lists at the end of last year, so most clients have already updated with no intervention needed. If you've explicitly configured your system to update from Cosmos, we recommend reverting to your distribution's default configuration. Most distributions can query a list of verified mirrors, automatically choose the fastest option, and automatically fail-over if your primary mirror is unavailable.