How to avoid?

[zbigis]

What is the best way to avoid site downtime as a result of moving your site from one server to another? A DNS change takes propagation time.

[sunken]

Before changing the DNS, make sure that you have the site duplicated at the new server. This will make the transition more seamless with less downtime. This does have a drawback though if you have an interactive site as some posts (such as in a forum) may go to the wrong server while the DNS is changing. But better than losing rankings and you can always temporarily shut off input from users until it's moved.

[ronit_3746]

Now let’s talk for a minute about moving from mattcutts.com to someotherdomain.com. All other things being equal, I would recommend to stay with the original domain if possible. But if you need to move, the recommended way to do it is to put a 301 (permanent) redirect on every page on mattcutts.com to point to the corresponding page on someotherdomain.com. If you can map mattcutts.com/url1.html to someotherdomain.com/url1.html, that’s better than doing a redirect just to the root page (that is, from mattcutts.com/url1.html to someotherdomain.com). In the olden days, Googlebot would immediately follow a 301 redirect as soon as it found it. These days, I believe Googlebot sees the 301 and puts the destination url back in the queue, so it gets crawled a little later. I have heard some reports of people having issues with doing a 301 from olddomain.com to newdomain.com. I’m happy to hear those reports in the comments and I can pass them on to the crawl/indexing team, but we may be due to replace the code that handles that in the next couple months or so. If it’s really easy for you to wait a couple months or so, you may want to do that; it’s always easier to ask crawl/index folks to examine newer code than code that will be turned off in a while.

[anantshri]

@ronit_3746, what zbigis what's to say is that he is moving his hosting provider and not domain.

and the best way as my suggestion is if site's a forum or something like that put a warning and stop posting for 2-4 hrs, and also keep a copy already duplicated before changing DNS.

DNS updates takes not more then that. when DNS update complete remove warning.

[puffin]

If its a dynamic site like a Forum , Blog or a topiste list I think best way is down the site first and move it so you won't miss anything visitors might leave.