What's the best way to switch domain aliases from one account to another in Google Apps for domain?

Question

I'm using Google Apps for Domain to manage mail, calendar, docs, etc for pupeno.com. I've created many other domain names and added to that Google Apps account as aliases.

Now I want to move some of those domains names to be aliases of another Google Apps account. What's the best way to change the alias? Any way to transfer? If I delete it for one account and activate it for the other, how long will I spend without access in the meantime?

Thanks

Update: completely rephrased the question and added screenshot because it was hard to understand.

Answer 1

You should clarify what do you mean with alias. For the purpose of this answer, I'm assuming you configured EXAMPLE.COM to map PUPENO.com at DNS level. In other words, EXAMPLE.COM points to the same IP of PUPENO.COM, using an A record or a CNAME DNS record.

In this case, the first step should be to decrease the DNS TTL, for instance to 1 hour, and wait at least 24 hours for the change to propagate. If the original TTL was equal or greater to 86400 (24 hours), better is to wait at least 36 hours.

Then, update the DNS record of EXAMPLE.COM to point to your new IP address (or domain) and wait for the chances to propagate.

In this case, the users will not experience any downtime because they continue to see the old site as long as their provider doesn't update the DNS cache.

If your site redirects to PUPENO.COM, simply change the redirect target to the new URL. Again, you will not experience any downtime.

Answer 2

I already did the migration. I just removed the domain from one account and added them as aliases into another already existing and running account.

According to Google the process of removing an alias may take up to 30 minutes. So I would plan a 30 minute downtime for mail and if you are serious about not losing email, change DNS entries accordingly*. Nevertheless, I removed them and added them immediately, sent an email and worked perfectly. I didn't even have to re-verify the names (not sure if that's a bug).

* What I would do is lower the time to live of the records to 5 minutes or so, then remove the MXs records so that mail stops being delivered and it's hold by the other servers; do the Google Apps switch and then re-establish the DNS records. Not sure if that's the most efficient or correct way to do it. As far as I know, all mail servers should retain undeliverable mail for up to 24hs.

UPDATE: for another domain it's been more than 5 days and I still can't add it to the other Google Apps account. So, be aware, that when you do this switch you may be out of business for more than a week. Here's the unhelpful information: http://www.google.com/support/a/bin/answer.py?hl=en&answer=56238