How to avoid downtime while moving websites between servers ?

[SaN-DeeP]

We are planning to upgrade one of our servers hence I have a few questions to help avoid major downtime for all websites during this upgrade.

1. We need to move from Server A to Server B on same hosting provider.

2. We have WHM/Cpanel Setup on Server A and opt for same on Server B

3. We have Red Hat Linux 9 on Server A and plan for better alternative on Server B (fedora, centos or rhl ent.)

4. We have custom nameserver for almost all websites on Server A and plan for same setup on Server B

5. Almost all websites are running on PHP/MYSQL system.

I would like to know how to avoid downtime and steps to keep in mind during our server move process.

thanks and regards,

[Floris]

What I do is make sure the sites work on both servers. open it on the new one. Then change the name servers. Once name servers are changed I delete the database on the old sever and point the config.php file from the old server to the database on the new one (make sure you have remote connection enabled for the remote host)

After a week I delete the old files and assume that a week is long enough for everybody to change the host to the new ip.

[alemcherry]

yes, floris mentioned the right procedure. make sure that your database server on new server can accept connections from outside, atleast for some time.

[SaN-DeeP]

What I do is make sure the sites work on both servers. open it on the new one. Then change the name servers. Once name servers are changed I delete the database on the old sever and point the config.php file from the old server to the database on the new one (make sure you have remote connection enabled for the remote host)

After a week I delete the old files and assume that a week is long enough for everybody to change the host to the new ip.

thats the best idea so far floris, thank you very much.

[encryption]

when I move clients between servers, the only "offline time" is the amount of time it takes to migrate clients from server to server. Once on the new location, I just paste IP based URL to the forum of the new server within the disabled message of the old server.

This way, you wont' even waste any time until the nameservers update. Members can instantly access your site within 2 minutes of the forum being migrated to the new server, regardless of whether the DNS has updated or not.

[---MAD---]

What I do is make sure the sites work on both servers. open it on the new one. Then change the name servers. Once name servers are changed I delete the database on the old sever and point the config.php file from the old server to the database on the new one (make sure you have remote connection enabled for the remote host)

After a week I delete the old files and assume that a week is long enough for everybody to change the host to the new ip.

How do you point it to a db on a different server / different host?

[Floris]

Enter the IP of the mysql server on the new host.
And add the host to the allow list for that mysql server/database

[---MAD---]

Enter the IP of the mysql server on the new host.
And add the host to the allow list for that mysql server/database

Can you expand on that please?

In config.php, what would I need to add / alter to be able to access the old server mysql database?

[Floris]

Don't touch the config.php on the new server.
But on the old server you change the master mysql host address from localhost to the new server mysql ip.

[---MAD---]

Don't touch the config.php on the new server.
But on the old server you change the master mysql host address from localhost to the new server mysql ip.

Oh right, that makes sense! Thanks a ton .

[express]

Also change your ttl value to 60 seconds in your dns zone 2 days before the change over.

Joey

[Floris]

Personally I work on the old site until it is done, then I change the whois info and the dns info. Then I update my computer HOSTS file to point the new IP to the host and test it. If it works on my system I continue working on the new site from the host (and no longer from the IP).

I also put in the footer template a little $variable that shows the IP of the site. So when I make changes I can first double check if the browser is on the old or the new ip, just to avoid confusion.

[jasonlitka]

Also change your ttl value to 60 seconds in your dns zone 2 days before the change over.

Joey

60 seconds is a bit overkill, but when I move a site I do actually change the TTL to 30 minutes a couple days BEFORE I move, that way I don't have to deal with the MySQL shuffling described in earlier posts. I simply copy everything over to the new server, turn it on, change the DNS, and turn off the old one. Most people will never even notice and the people who were online at the time will get updated records within 15 minutes or so.

[---MAD---]

Personally I work on the old site until it is done, then I change the whois info and the dns info. Then I update my computer HOSTS file to point the new IP to the host and test it. If it works on my system I continue working on the new site from the host (and no longer from the IP).

I also put in the footer template a little $variable that shows the IP of the site. So when I make changes I can first double check if the browser is on the old or the new ip, just to avoid confusion.

What would that variable be ?

[express]

60 seconds is not overkill at all. When it comes to high profile sites time is money and 15 minutes is not good at all.


Joey