Dec 15 2008
Email Hosting Migration - Zero Downtime!
Recently I’ve been receiving a number of requests from customers to migrate their hosting service to the new cPanel-based Linux server.
But some customers are not migrating for fear that there might be downtime disrupting their email service during the few hours of migration. Can there be zero downtime?
I don’t know how other hosting providers do it. But for me, the answer is yes! You can still send and receive as usual! Firstly, you make a small change to the account in your email software to connect to the old mail using IP addresses. Secondly, you create another account to connect to the new mail server after the migration.
For the old account, you simply change the “incoming mail server” from pop.yourdomain.com to the IP address of your current incoming mail server, and change the “outgoing mail server” from smtp.yourdomain.com to the IP address of your current outgoing mail server. You can get the IP address by doing a “ping” test to pop.yourdomain.com and smtp.yourdomain.com. Or you can just ask me and I’ll send you the IP addresses.
Once you enter the IP addresses for both “incoming mail server” and “outgoing mail server”, you can retrieve your emails from the old mail server and send emails as usual, before, during and after the migration. Please do download all emails to your PC within a few days after the migration, as your email service on the old mail server will not be kept long.
For the new account, you create one in your email software in order to connect to the new mail server. The settings are a bit different and I’ll send to you everything you need. You can create the account any time but it will work only after the migration.
In addition, please send me the list of your current email addresses under your domain name so that I can help create the addresses on the new server. This ensures that incoming emails after the migration will not get lost or bounced.
Easy migration! No more migrane! :-) Find out more if you are interested to migrate your hosting too.
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Hope this helps. Playing around with DNS and some pre planning can avoid the downtime and make it transparent.
http://www.1.com.my/2008/03/15/zero-downtime-email-migration-for-furniweb/
http://www.1.com.my/2008/12/03/microlink-email-migration/
Thanks Pin. Wonderful. Zero downtime and transparent for both web and email. Can share the steps, technically?
But it seems it needs cooperation from previous host. If without their help, as in my many cases, possible to achieve that?
Two key things. Break migration to two stages.
1. Switch DNS BUT maintain the same Zone setting. Not actual migration, but bypass Propagate process which cause downtime.
2. After a day or two, update the MX to the new mail server. MX change takes effect faster than DNS switch. Make sure list of users in both mail servers are the same. During MX change, some email trapped in old mail server but not lost. Tricky, keep old mail server POP, SMTP and Webmail pointing in order for them to download old email trapped.
Perhaps the one last thing you should, is to talk to the previous host.. haha. You dont want them to terminate the email server before expiry date and lost all the trapped email
Thanks Pin for sharing
[...] To transfer your email service to the new server, please first send us a list of your current email accounts. I’ll create on the new server. It is possible to achieve zero downtime for email service by checking your emails from both old and new serveres at the same time. Please read here for more information. [...]
[...] However, your emails on the current server, if any, cannot be migrated over. Your users need to download the emails to their computers. But you can keep on sending and receiving emails during the migration. Read here for more information. [...]