A network storage appliance comprises solid state disks, a network interface adapter communicatively coupled to the solid state disks and a host client, a non-volatile semiconductor memory device communicatively coupled to the solid state disks and the network interface adapter, and a CPU communicatively coupled to the non-volatile semiconductor memory device and the network interface adapter. The non-volatile semiconductor memory device can receive data from the host client via the network interface adapter, store the data temporarily, and transfer the data to one of the solid state disks. The CPU can receive a write request from the host client via the network interface adapter, determine whether or not the non-volatile semiconductor memory device is available to store the data, initiate the network interface adapter to perform the transfer of the data from the host client to the non-volatile semiconductor memory device if the non-volatile semiconductor memory device is available to store the data, and initiate the network interface adapter to broadcast a query to one or more external storages if the non-volatile semiconductor memory device is not available to store the data.