| 摘要 |
Device, method and computer program for improved copy on write functionality within an SSD (Solid State Drive, Solid State Disc (Disk), Solid State Device) and includes providing, in the memory of a device, an indirection data structure, which includes a master entry for cloned data, the master entry having a reference to one or more indexes and a clone entry for the cloned data, the cloned entry having at least one of: a reference to a master index, a reference to a next index, and a value indicating an end of a data structure. The device and method includes traversing one or more copies of the cloned data using one or more of the references by means of a computer processor. The indirection data structure may comprise a plurality of physical addresses and may form a part of a circular linked list wherein the master entry and/or the clone entry for the cloned data comprises a reference to a master index and a reference to a next index. The indirection data structure may also be a part of a single linked list in which an entry in an index provides an indication that the index is a master index. The reference may comprise entries in a flat indirection table or a tree data structure for logical block addressing. The improved copy on write functionality comprises an improved namespace copy functionality. The device or method may further comprise setting an indicator for one or more packed logical blocks to indicate that the packed logical blocks are closed. The method may comprise reviewing an entry during a garbage collection process, determining that the entry contains a cloned indicator and determining that the entry in the garbage collection process is a valid entry not to be deleted if determined the entry contains a cloned indicator. The device may include a further first device to include stored instructions in memory, the instructions to include the indirection data structure , master entry etc, and may be a Peripheral Component Interconnect Express (PCIe) device. |
