US Patent 8713252 Transactional consistency scheme

A proxy manages write operations between devices that initiate write operations and one or more storage devices that store data for the write operations. A write log buffers the data for the write operations while the proxy waits for acknowledgments back from the storage device. The proxy is configured to copy at least some of the data from the write log into an overflow log when the data from the write operations is about to overflow the write log. The proxy device is further configured to maintain data consistency by delaying or blocking read operations until associated data from previously received write operations is acknowledged by the storage device.