How To Switch Hosting Providers Without Downtime?
If you follow the steps below you should be able to transition from one host to another without any downtime to your web site.
Create A New Account
Firstly you need to choose your new hosting provider, once you have chosen that provider sign up for the chosen hosting package and once the new account is setup you can move on to the next step.
Backup All Your Files From Your Old Account
This is a relatively simple process, but can be time consuming depending on the size of your web site. Go to your old hosting account and download all the files via FTP, and backup any databases in use. Remember that you cannot cancel this account yet even though you have backed up all your files.
Upload All Your Files To Your New Account
Once you have backed up your files on your old hosting account, it is time to go to your new hosting account and upload the backups via the new hosts FTP.
Create Your Mail Accounts
To avoid losing any of your email when you later change your domain name server addresses, it is imperative that you now create all the same email accounts that you had with your old hosting provider in your new hosting account. Once this has been done, all email addresses on the new account should match the email address on your old account.
Checking of Your Files and Links
Now it is time to check all the pages of your web sites and verify that all links are working correctly on your new host. To do this you will need to create a temporary URL to the web site. A quick and easy way to do this is to create a sub domain of another URL and point it to your new web site by the way of mirroring. Any good web hosting provider should provide you with the ability to create temporary a URL so you can test your new site.
Changing Your DNS (Domain Name Server)
If you are now certain that your files have all been uploaded correctly and the links within your site are working correctly, you can change your DNS (domain name servers). Your new host should have provided you with their DNS settings. If they have not, contact them and ask what addresses should be used for your domain name. Usually the addresses will look like this, ns1.domainname.com, ns2.domainname.com.
The place to change the DNS addresses is whoever your domain name is registered with. If you registered the domain name through a registrar, you will need to login to their control panel and change the DNS servers there. If it was registered with your old host, you will need to login to their control panel and change the DNS entries there.
Wait For DNS Changes To Propogate
After you have changed your DNS (domain name servers) you will need to wait between 24-48 hours for your domain to propogate across the internet. During this waiting period your site will still be served from your old hosting account, as the DNS propogates your site will be served from your new host. Once the propogation has completed all requests to your domain will be served from you new host.
Cancel Your Old Account
Make sure you wait at least 48 hours for the domain name to propogate, and make sure that your domain name is resolving to your new hosting account before cancelling your old account.
By following these steps you should now have successfully transferred your web site from your old host to your new host without any downtime.