A method of transferring data from an active memory to a mirror memory in an Fault Tolerant, FT, Server system, the FT Server system comprising an active processor subsystem providing output data and including one or more processors, the active memory, a Field Programmable Gate Array, FPGA, and an input/output module and a mirror processor subsystem including one or more processors, the mirror memory, a Field Programmable Gate Array, FPGA, and an input/output module, the method comprising the steps of: Reserving a portion of memory using BIOS of the FT Server system at boot time; Loading and initializing an FT Kernel Mode Driver; Beginning processing, by the FT Kernel Mode Driver, a command to enter Mirrored Execution; Loading and initializing, by the FT Kernel Mode Driver, an FT virtual machine Manager, FTVMM, including a Second Level Address Table, SLAT, into the reserved portion of memory and synchronizing all processors in the FTVMM; Tracking memory accesses using the SLAT in the reserved portion of memory; Entering a Brownout memory copy phase 0, by executing a full memory copy of the active memory to the mirror memory of the mirror processor subsystem while keeping track of dirty bits, D-Bits, in the SLAT to track memory writes by all software in the FT Server system; Clearing all of the D-Bits in the SLAT; Entering Brownout memory copy phases 1-4 and tracking all D-Bits by: Collecting the D-Bits; Invalidating all processors cached translations for SLAT; Copying the data of the modified memory pages from the active memory to the mirror memory; Entering a Blackout memory copy phase by pausing all the processors in the FTVMM, except one Processor #0, and disabling interrupts in the FT Kernel Mode Driver for processor #0; Copying the pages dirtied during the previous Brownout memory copy phase from the active memory to the mirror memory; Collecting the final set of recently dirtied pages; Transferring the final set of recently dirtied pages to the mirror memory using the FPGA (Field Programmable Gate Array); Using the FPGA and Firmware System Management Module, SMM, to generate a warm reset and enter a state of Mirrored Execution; Unloading the FTVMM and exiting into FT Kernel Mode Driver to cease operation of the FTVMM; and Resuming normal FT Server system operation. Reserving a portion of memory using BIOS of the FT Server system at boot time; Loading and initializing an FT Kernel Mode Driver; Beginning processing, by the FT Kernel Mode Driver, a command to enter Mirrored Execution; Loading and initializing, by the FT Kernel Mode Driver, an FT virtual machine Manager, FTVMM, including a Second Level Address Table, SLAT, into the reserved portion of memory and synchronizing all processors in the FTVMM; Tracking memory accesses using the SLAT in the reserved portion of memory; Entering a Brownout memory copy phase 0, by executing a full memory copy of the active memory to the mirror memory of the mirror processor subsystem while keeping track of dirty bits, D-Bits, in the SLAT to track memory writes by all software in the FT Server system; Clearing all of the D-Bits in the SLAT; Entering Brownout memory copy phases 1-4 and tracking all D-Bits by: Collecting the D-Bits; Invalidating all processors cached translations for SLAT; Copying the data of the modified memory pages from the active memory to the mirror memory; Collecting the D-Bits; Invalidating all processors cached translations for SLAT; Copying the data of the modified memory pages from the active memory to the mirror memory; Entering a Blackout memory copy phase by pausing all the processors in the FTVMM, except one Processor #0, and disabling interrupts in the FT Kernel Mode Driver for processor #0; Copying the pages dirtied during the previous Brownout memory copy phase from the active memory to the mirror memory; Collecting the final set of recently dirtied pages; Transferring the final set of recently dirtied pages to the mirror memory using the FPGA (Field Programmable Gate Array); Using the FPGA and Firmware System Management Module, SMM, to generate a warm reset and enter a state of Mirrored Execution; Unloading the FTVMM and exiting into FT Kernel Mode Driver to cease operation of the FTVMM; and Resuming normal FT Server system operation.