Patent ID: 7266636

Claim:
A magnetic tape drive assembly configured to write data to magnetic tape, said data in the form of at least one transaction of data with a synchronize command to synchronize said transaction, said data to be synchronized, comprising: a magnetic tape drive configured to write writing data to magnetic tape; a buffer configured to store said transactions of data for writing data to magnetic tape; deferred sync logic configured to communicate with a non-volatile store, said non-volatile store for storing data, said deferred sync logic configured to perform the operations of: storing said data of a transaction to be synchronized to said non-volatile store; upon storing all said data of said transaction to said non-volatile store, responding with a Command Complete; supplying said data of said transaction to said buffer for writing to said magnetic tape; repeating said storing, responding, and supplying operations for subsequent transactions of said data to be synchronized; and providing a Deferred Synchronize Command specifying at least one previously supplied said transaction of data, said Deferred Synchronize Command comprising a command for writing data of an identified transaction to magnetic tape; and tape drive logic configured to respond to a Deferred Synchronize Command identifying a transaction previously supplied to said buffer, said tape drive logic configured to perform the operations of: operating said magnetic tape drive to write all data of said identified previously supplied transaction of said buffer to said magnetic tape, and to write data of any transactions of said buffer received prior to said identified previously supplied transaction of said buffer to said magnetic tape; and providing a Tape Command Complete subsequent to operating said magnetic tape drive to write all data of said identified previously supplied transaction to said magnetic tape and to write data of any said transactions received prior to said identified previously supplied transaction to said magnetic tape, whereupon said data of said previously supplied transaction stored to said non-volatile store may be overwritten.