Redundancy Between two Data Centers

Thanks Simon!

Right, in typical scenario, the traffic will go/might go to both data centers.

In my case, the telco will use BGP to advertise IP addresses of one location only. In case connectivity to primary data center fails, telco will advertise the same IP addresses from second data center. Not sure if GSLB it's a good idea here... Maybe only if they can advertise different subnets from both data centers.

Can I have four devices in one HA group?

In case of ESX/storage issue (in primary data center), the virtual IPs will be advertised from LTMs in second DC, correct? I've planned to use the same server IPs in both data center (at least from load balancer standpoint).

In case the entire DC going dark, it will be much simpler scenario, all traffic will be sent to second DC.

I have a problem how to manage cases of partial impact, for example the virtual environment is down. In this scenario, from telco perspective all works fine in first DC, and all traffic from the client will continue to come to that location, but LBs and all servers will be down...

Thanks!