How can I have my own dns server to switch server for websites ?

Hello,
I run two VPS servers from contabo, Recently I purchased third server and I installed DNS server manager on it after a clean install of CWP pro, although cwppro not required for it but I purchase license because of other reasons. Now I want this third cwp server where dns server and manager is installed to act as a ns1.domain.com and I want previous two servers to act as ns2.domain.com and ns3.domain.com
So far I have configured added dns server manager and on 1st and 2nd server i have configured slave dns-manager inside dns function. It can push domains to dns server manager on third server.

1. so far its working. but in dns server manager at dashboard when i start, restart, or stop, whatever button i click it does nothing. (Status for named. Inactive). How do start this.?

2. My second question is how do I configure namservers for all all servers. So that I can have ns1.domain.com and ns2.domain.com and ns3.domain.com namservers which I give to my clients when they purchase an account from me.

As of now I have setup and created two different ns1 and ns2 on both old servers. I want to use dns server manager so that I can switch my cliens account from one server easily without delay and without them knowing it.

presenlty I am using cloudflares dns manager to do so, when i transfer client acount from one account to another by cwp to cwp migration I change dns A record in cloudflare dns manager.

Can someone help me understand this. How can i do this,

In godaddy i see they always provide same nameservers to clients no matter which server you are using, I want to achieve this.

Waiting for help from community.

you need cloud concept and some logic
cmiiw... i was use this concept at 2000-2005 lol
no cloud system at that time and i use CPANEL (the only one panel / the best one 'at that time' ) + whmcs

at domain manager you just need setup child

ns1.domain.tld IN A 1.1.1.1 server A
ns2.domain.tld IN A 2.1.1.1 server B
ns3.domain.tld IN A 3.1.1.1 server C
ns4.domain.tld IN A 4.1.1.1 server D

domain.tld IN NS ns1.domain.tld
domain.tld IN NS ns2.domain.tld
domain.tld IN NS ns3.domain.tld
domain.tld IN NS ns4.domain.tld

at whmcs i set NS :
ns1.domain.tld
ns2.domain.tld
ns3.domain.tld
ns4.domain.tld

when my client register via vhmcs let say client-domain.tld
it will create to server A
and set ns to ns1 2 3 4
then sync (with my friends tools) make clone to B C D

of course it was not cloud but almost like cloud system...
visitor client-domain.tld will load from nearest server
and that only work 50%-70% ... sometimes it always push to A

We stop play hosting and never update until few month ago i try to make money from hosting ( oot: im shocked... not easiest like b4 to sell hosting)

yes its very complicated thing, Like if i clone websites to all three servers and its wordpress site, how do i achieve database synchronisation.

And I dont understand the whole point of dns server manager thing, what is its porpose and why use it.

I do face problems when I want to switch my clients account from one vps to second vps or third vps, every time I do that I need to change a records of my my clients dns to point the website to new address, and I use cloudflare account to do this.

Acctualy I reque a software or interface like cloudflare where I can change my clients dns without them knowing, I am a freelance and I sell server to my own clients only, not selling it as provider. and also provide technical support to them, for keeping thier site optimize, thats why i host thier site on my own vps purchased from contabo.

Is there any softer or dns manager like cloudflare upon which i can manage my clients dns records/zones ?

Just buy aws cloud or google cloud

well little oot..

And I dont understand the whole point of dns server manager thing, what is its porpose and why use it.
>> try new concept.. and today we found the cloud server lol

how do i achieve database synchronisation.
i was use remote database in one server actualy lol
and use some "like" proxy stuff

yes its very complicated thing, Like if i clone websites to all three servers and its wordpress site, how do i achieve database synchronisation.

And I dont understand the whole point of dns server manager thing, what is its porpose and why use it.

I do face problems when I want to switch my clients account from one vps to second vps or third vps, every time I do that I need to change a records of my my clients dns to point the website to new address, and I use cloudflare account to do this.

Acctualy I reque a software or interface like cloudflare where I can change my clients dns without them knowing, I am a freelance and I sell server to my own clients only, not selling it as provider. and also provide technical support to them, for keeping thier site optimize, thats why i host thier site on my own vps purchased from contabo.

Is there any softer or dns manager like cloudflare upon which i can manage my clients dns records/zones ?

Correct me if I'm wrong - you are trying to load balance your website traffic for your clients? DNS by itself won't do this. You would need some kind of load balancer software to do this in case one goes down. Having two or more A records for the same domain will result in a time out for the single client that resolves the IP to a dead or unavailable server. Perhaps a better direction to look into setting a load balancer for your third server.

LJB