Depending on its location, the virtual failover client (VFC) uses system resources from the Recovery Series appliance or hypervisor. These resources include processors, memory, and storage. Running a VFC on an appliance or hypervisor can impact the performance of other operations, so it is important to verify that the appliance or hypervisor has sufficient resources before creating a VFC. For instructions on monitoring system load for a Recovery Series appliance, see Unitrends system resource considerations for Windows instant recovery. See the documentation for your hypervisor for instructions on monitoring its system load.
When you create a VFC, you assign it processors and memory to use in audit and live state. In all other states, the VFC uses only 1 processor and 1 GB of memory. The appliance creates a VFC with a disk the same size as the disk on the original client. However, because the disks expand dynamically, the amount of storage actually used on the appliance or hypervisor is equal to the amount of space used on the original disk rather than the size of the disk itself. As the amount of storage space used on the original client increases, the amount of storage the VFC uses on the appliance or hypervisor increases. In many cases, the amount of storage actually used for the VFC is less than the size of the disk.