Consolidate DNS


We do web hosting and using Virtualmin GPL on most of the machines (about 80 machines). Currently each server is running its own DNS server and we have separate nameserver records for each server to be given to the clients such as

But now we like to consolidate all DNS to 3-4 machines running in different physical locations. And we plan to modify the DNS of all the domains hosted to these new DNS machines. We have tested now is setup new DNS machines and installed Webmin on them. And defined these machines in “Cluster Slave Servers” with “Create secondary on slave when creating locally” set to yes in all 80 Virtualmin servers.

Everything looks fine as if we add/modify anything in any of the Virtual Servers, the DNS records at the new DNS servers are affected accordingly.

My question is is this architecture fine, any expert opinions please?

Also what will happen if any of the DNS server is unreachable while the DNS record is being changed at 1…80 VirtualMin servers?

Thanks in advance,


Architecture looks okay to me! In techy terms, your 80 hosting machines will be “hidden masters” that hold the master zones, distribute them to your 3-4 slaves, and only those slaves host the zones for the net.

If one server is unreachable, that’s a problem only while a new zone is being created. If it’s just about changing records, those changes will be pulled in automatically (via zone transfer) when the server becomes reachable again.

But if it is down when a new master zone is created, that zone will have to be manually created on the slave when it’s available again. Webmin will not “re-try” to create slave zones if one of its DNS cluster slaves is unreachable. It’ll just display a warning message about that.

(To avoid having to create the zone manually, you could of course turn the DNS feature for the domain in question off and on again, that will delete and re-create the zone on all slaves.)

Thanks a lot Locutus for very quick answer.