Veeam included with backup & replication features. On vm replication, by default it provide async replication from Site 1 to Site 2. This is typical supported deployment & need to use same hypervisor platform.
Hyper-V -> Hyper-V
Vmware -> Vmware
Default Scenario
1. Production VM from Site 1 replicate to Site 2.
2. Site 2 VM is a replica VM in offline state
Result: No error reported by Veeam. Able to perform failover and failback
Scenario 1 : One Source to many
1. Production VM from Site 1 replicate to Site 2
2. Production VM from Site 1 replicate to Site 3
Result: No error reported by Veeam. VM able to replicate to target side.
Note:- Make sure both vm replication scheduling is not running at the same time. You need to configure different time & does not conflict each other.
Scenario 2: One source to one target & replicate back to source
1. Production VM from Site 1 replicate to Site 2 (Vm_Replica)
2. VM_Replica from Site 2 replicate back to Site 1 (VM_replica_replica)
3. Configure different scheduling & does not conflict with existing schedule.
This approach is because customer do not want to overwrite existing production VM. VM_Replica from Site 2 is replicate back to Site 1 as VM_Replica_Replica. Customer want fast replicate to Site 1 rather than wait for failback synchronization.
Result:
1. Able to replicate from Site 1 to Site 2
2. Site 2 replicate back to Site 1. Will encountered an error "Changed block tracking is not enabled. one or more snapshot present." Warning message but replication is successful. Tested with data changes.
Not recommend scenario & must practice in caution especially failover/failback.
Scenario 3: One Source to Target, One Target to another Target
1. Production VM from Site 1 replicate to Site 2 (Vm_Replica)
2. VM_Replica from Site 2 replicate to Site 3 (VM_replica_replica)
3. Configure different scheduling & does not conflict with existing schedule.
Result:
1. Able to replicate from Site 1 to Site 2
2. Site 2 able to replicate to Site 3. Will encountered an error "Changed block tracking is not enabled. one or more snapshot present." Warning message but replication is successful. Tested with data changes.
Not recommend scenario & must practice in caution especially failover/failback.
Above are few test scenario that i've performed, no guarantee it will work since CBT cannot be enabled for Scenario 2 and 3.
Good luck on your testing!