Multi-Server

[djcart]

"Hey! I'm considering expanding my infrastructure. I'd like to add another server with DirectAdmin and make use of the Multi-Server option. Has anyone here had any experience using this feature? How does it work exactly? What are the pros and cons?"

 

[Zhenyapan]

It allows you to spread DNS zones between few servers, so you can use same NSs, also you can control USERNAMES - they will not repeat in this servers, so you can move some user from one server to another without worry they will be merged into one account.

 

[Richard G]

We use this for years and switch secondary ip's in the nameservers so we have different ip's.

Only con might be that if you want to move a user to the other server, it will complaint that the user or domain is already present.
In that case you have to temporarily disable the checks or the multiserver and enable it after moving.

Or delete the user on the old server after creating a backup but before importing on the other server is also an option.
We like to use the first option in case we might have forgot something or the user had something he needed in the .backup_exclude_paths file so we normally don't use the user check.

 

[djcart]

Hey, thank you for the information. I have a question regarding configuration. If I add servers 2 and 3, should I duplicate the settings from the first configuration in the DNS zone settings? Of course, the second and third servers will use different domains, but the DNS zones look like this: ns1.server1.com and ns2.server1.com.

How about the reliability of such a multi-server setup? What happens if server 2 or server 3 goes down? Can I easily restore users to another server during the repair?

 

[Richard G]

Can I easily restore users to another server during the repair?

There is a difference between users and DNS. The multiserver is a DNS only backup, so it can not be seen as a redundant backup.
If server 2 or 3 goes down, then all DNS records only exist on server 1. This will point DNS to server 2 or 3 for the domains on server 2 or 3, but this is mostly so for example nameservers know the domains still exist and retry sending mail later for example.
And for other systems to see the domain exist but there is a temporary issue.

If you have backups from the users, yes they you can easily restore them to any other server.

If needed you can delete DNS records which are present. In a multiserver setup, all records which are NOT present on the local server will have 2x a NO visible. Once on Local data and once on Local mail in DNS administration.

But to restore users, you have to have users backup, as said, multiserver is only DNS and not a redundant server for user accounts.

Multi-Server Setup | Directadmin Docs

DirectAdmin Knowledge Base

docs.directadmin.com

 

[djcart]

Thank you for this information. I have one more question: How can we best protect ourselves in this configuration in the event of a master server failure?

 

[Richard G]

How can we best protect ourselves in this configuration

As for DNS, this way, with multi-server setup, so the domain databases are always present at another server.
As for user accounts.... create external backups and/or put in your terms that customers are responsible for their account backups themselves.

If you ment something else, please specify.

 

[Zhenyapan]

in the event of a master server failure?

multi-servers equal, there is no master. If one dropped and reinstalled - you can run named rewrite tally and all DNS zones from older one will be moved copied to new one. I'm using 3 servers for 3 NSs. If you about another data - as Richard say - backups only.