Ubuntu – How to switch to a closer Ubuntu mirror

Ubuntu attempts to select a local mirror of the repositories that are geographically close to you. The partner repo doesn't have any mirrors because of copyright issues (AFAIK -- it's non-free software) so you end up using the London-hosted copy. PPAs are probably the same.

As you're in the Caribbean, I imagine traffic UK-bound would have to hop through the US before going trans-Atlantic to London. That's a long way for something to travel and if any of the links are bad or lossy, traffic can grind to a slow speed. At the least, response time is very slow.

If you want to test this further you can run ping archive.canonical.com and see what you get for a response time (I'm in England and get ~26ms). And as a general speedtest to London, you can run wget http://london1.linode.com/100MB-london.bin (1.3MB/s here).

As for fixing the problem... Canonical either need more, geographically-distrubuted servers for the partner repo, or you need to move closer to London.

I answer myself:

• Setting no_proxy solve the problem:

export no_proxy="192.168.0.0/16,localdomain"

but warning is displayed:

WARNING: Failed to read mirror file

No valid mirror found 

While scanning your repository information no mirror entry for the 
upgrade was found. This can happen if you run a internal mirror or if 
the mirror information is out of date. 

Do you want to rewrite your 'sources.list' file anyway? If you choose 
'Yes' here it will update all 'lucid' to 'precise' entries. 
If you select 'No' the upgrade will cancel.