A veeam and very interesteing feature is remote VM replication that it means, in fault case you can start, on remote site, relative VM.
here are some interesting information.
Replication Theory
Replicating a VMware virtual machine means creating a “twin” of the production virtual machine on a remote site in a ready-to-use state. Native VMDK file is stored uncompressed together with the VMX configuration file already registered in the target vSphere environment, so you can immediately power on the required VM on demand. Whenever you have problems, and whatever those problems you might have with your production application, you can always start its replica in just a few seconds from another location. In comparison with backup, replication shows faster recoverability and very quick recovery time objectives (RPOs) because instead of restoring data from the backup and registering the VM, you simply need to power-on a spare clone of a failed VM. Additionally, replicated VMs are flexible in handling since they can be used on the same site to accommodate a SAN failure or even off-site to accommodate a site-wide outage.
2 in 1 backup feature
Veeam Backup & Replication (a part of Veeam Availability Suite) performs both backup and replication for VMware and Hyper-V, so you get a 2-in-1 solution. It performs image-based replication with compression, deduplication and changed block tracking (CBT) technologies, which reduce traffic and speed up data transfer.
Veeam's replication is similar to forward incremental backup. During the first job run, Veeam Backup & Replication creates a full virtual machine copy and then catches only the VM changes during subsequent job runs. Each replica has a number of restore points (like backup increments) which work as restore points for failover. You can configure up to 28 replica failover points with a Veeam replication job. Replication traffic floats block-by-block through a data pipe organized between the source and target hosts by means of Veeam's transport services.
Replica Backup Validation
Veeam Backup & Replication allows you to check every created VMware replica for recoverability without any manual work from you and right after your VM replica restore points are ready. When performing a SureReplica job, Veeam Backup & Replication validates replicated data for consistency, checks its configuration accuracy and tests replica for complete reliability by running it to the required restore point in an isolated virtual lab
http://www.veeam.com/leveraged-data-virtual-lab.html
About DR remote sites on ESXi it would be important to know that you do not need to purchase additional licenses about remote sites.
The only exception where you will need the Veeam Backup & Replication licenses for both the production and DR sites here is when your target host is running VMs that you are also backing up or replicating.
[original Veeam article http://www.veeam.com/blog/how-to-start-with-vmware-vm-replication-using-veeam-availability-suite-2.html]
