Re: Moving web server to new IP

[Chris Jones <chris@chris-j.net>]

Hi Simon,

Drop the TTLs on all of these sites down to something low (eg 1minute) 
about a week before hand. This should cut down on the number of requests 
that hit the old IP addresses. Then, simply switch the DNS records over 
to refer to the new IP range, and establish a proxy on the old IP addresses.

Sure, some requests will still hit the old addresses, but they'll be few 
and far between. The same should also be true of mail.  Then, once 
there's nothing more hitting those IP addresses, you can safely 
decommission them.

Regards,
Chris Jones

Simon wrote:
> Hi There,
>
> I know this is strictly not a debian question, but i will be using
> debian todo it!
>
> I need to move our web server to a new IP range. This is hosting
> around 300 websites, about 250 on 2-3 IPS (standard name based virtual
> hosts) and the rest on their own IPs (SSL hosts). All running on
> apache/php/mysql.
>
> Im wondering how i can achieve this over a period of a week rather
> than all in one go.
>
> My thoughts are to set up some sort of proxy to proxy the requests
> from one IP range to another. But, this would result in wierd hit
> stats (coming from the proxy IP rather than the client IP - i think).
>
> Im wondering if this could be done with netfilter somehow? or some 
> other way?
>
> Moving mail and DNS is easy as i can use pedrition for the mail proxey
> and just run dual name servers until they are sorted as they are low
> overhead anyway.
>
> Any input is appreciated.
>
> Simon

--
Chris Jones
chris@chris-j.net