Possible Cause  | Possible Resolution  | 
On VMware ESX/ESXi 4.x hosts: The VRA does not have enough resources.  | Either vMotion some of the protected VMs to another host or expect more frequent bitmap syncs.  | 
On VMware ESXi 5.x or Microsoft Hyper-V hosts: The VRA does not have enough reserved memory.  | Check that all the VRA memory is reserved.  |