performance impact of large /etc/hosts files

[Alex Zbyslaw]

Erich Dollansky wrote:

> Alex Zbyslaw wrote:
>
>> Erich Dollansky wrote:
>>
>> Assuming I've understood your initial post correctly, then I do the 
>> same, redirecting some dozen ad sites to a  local web server.  With a 
>
>
> this is how I started. Then friends did the same. We exchanged the 
> files. We added hosts files from the Internet.
>
>> dozen or so aliases I've never noticed any difference in performance, 
>> but I suspect you have rather more than that :-)  I could never quite be 
>
>
> I also do not notice a difference. Especially news sites with all the 
> ads are even faster as there is no waiting for the ads.
>
>> I'm pretty sure you could also do the same with a local DNS server, if 
>
>
> This is what I am thinking of since some time but I never did.
>
> It would have the additional advantage of faster name resolution.
>
> Having a DNS on every machine seems like a real overkill to me.

Why would you have DNS on every machine?  I don't know what your setup 
is like, but any separate network (like your home, your office) would 
only need one(*) DNS server for the entire network.  Of course, everyone 
then gets their ads blocked, not just you :-)  No way to make it 
per-user that I can think of.  But, you could run 1 DNS and only point 
hosts which wished to participate in the ad blocking at that DNS server 
and let others do their resolution however they normally do it (ISP DNS, 
company DNS).

>
>> There's no clean solutions to getting different lookups per-user that I 
>
>
> The clen solution is hosts.

It's not per-user, which was what you originally asked.

>
>> Unclean solutions might include something like making the hosts file 
>
>
> This is something I would like to avoid.

If you want different name resolution per user, then I see little 
alternative to something like this.  I'm not even sure it's possible, to 
be honest, but then name resolution was never expected to be per user :-(

--Alex

Yes, you should probably have a second, slave DNS if your network is 
more than a couple of  hosts.  Setting up a DNS is not actually that hard.