How should I configure an identical server for failover purposes?
Posted on 2014-07-28
OK, I'll try to keep things as simple as possible.
We have one domain.
We have a virtual host (ServerA) that has 8 virtual machines stored on it.
We have an identical host (ServerB) that has copies of all 8 virtual machines.
The virtual hosts themselves aren't accessed directly. The virtual machines are what the users access.
The 8 VMs on ServerA have static IP addresses and certain names.
The 8 VMs on ServerB which are copies of the 8 VMs from ServerA have dynamic IPs and have an underscore in front of their name. This allows all 16 VMs to be on our network at the same time.
In the event ServerA was to fail, I want to be able to:
- remove the underscore from each VM on ServerB
- give each VM on ServerB the static IP their brother's had on ServerA
- reboot each VM and have them now be the primary, active VMs
I'm trying to minimize downtime. I know there are solutions out there that can do all of this automatically like VMware HA but these require a SAN or vSAN which we don't have money for.
That being said, I ran into an issue when running the test below:
- shut down VM1 on ServerA
- assign _VM1 on ServerB the static IP address VM1 had on ServerA
- rename _VM1 to VM1 and reboot
When the "new" VM1 comes back up, we can't login because of a domain trust issue. This requires us to login locally, remove the VM from the domain, reboot, add it back to the domain and reboot once more.
This adds an additional XX minutes which I'd like to see if we can avoid.
I'm assuming this is because the original VM1 was already on the domain so Active Directory doesn't like that there is another VM1 trying to login to the domain.
Can I do something to prevent this like remove VM1 from AD in the event of a failure?
Any help would be appreciated.