A first node (100, 200), comprising: a volatile memory (130; 260); a group table (110, 210) including a group comprising a plurality of group address ranges (114, 215, 217) that are mapped to a memory address range of a nonvolatile memory, NVM,, each group address range, of the plurality of group address ranges, including a copy-on-write, COW, range (116, 225, 227), with a first memory address of the memory address range being associated to data to be copied to the volatile memory (130, 260) if the first memory address is mapped to the COW range and a write access is requested for the first memory address, wherein said each group address range of the group address ranges is to be associated with one of a plurality of ready flags; and a controller (120, 250) configured to update the data copied into the volatile memory upon receiving a write request, wherein the controller is further configured to transfer data associated to group address ranges from the first node to a second node (150, 290) according to an order determined by the group table, in response to a synchronization command, said synchronization command including a synchronization address range, said group address ranges being determined to be associated to said synchronization address range by using said group table,, wherein the controller is to transmit a marker after the transfer is complete, the controller is to write the copied data to the NVM after the second node acknowledges the marker, and wherein: the controller is to set the ready flag of a group address range, if the data associated to the group address range is to be transferred to the second node, the controller is to reset the ready flag of all but the last of said group address ranges after their data is transferred to the second node and to reset the ready flag of the group address of which data is transferred last after the second node acknowledges receipt of the marker and the copied data is written to the NVM. a volatile memory (130; 260); a group table (110, 210) including a group comprising a plurality of group address ranges (114, 215, 217) that are mapped to a memory address range of a nonvolatile memory, NVM,, each group address range, of the plurality of group address ranges, including a copy-on-write, COW, range (116, 225, 227), with a first memory address of the memory address range being associated to data to be copied to the volatile memory (130, 260) if the first memory address is mapped to the COW range and a write access is requested for the first memory address, wherein said each group address range of the group address ranges is to be associated with one of a plurality of ready flags; and a controller (120, 250) configured to update the data copied into the volatile memory upon receiving a write request, the controller is to set the ready flag of a group address range, if the data associated to the group address range is to be transferred to the second node, the controller is to reset the ready flag of all but the last of said group address ranges after their data is transferred to the second node and to reset the ready flag of the group address of which data is transferred last after the second node acknowledges receipt of the marker and the copied data is written to the NVM.