System and method for limiting fragmentation

摘要

A method and system are disclosed for controlling the storage of data in a storage device to reduce fragmentation. The method may include a controller of a storage device receiving data for storage in non-volatile memory, proactively preventing fragmentation by only writing an amount of sequentially addressed logical groups of data into a main storage area of the storage device, such as multi-level cell (MLC) flash memory, and reactively defragmenting data previously written into the MLC memory when a trigger event is reached. The system may include a storage device with a controller configured to perform the method noted above, where the thresholds for minimum sequential writes into MLC, and for scanning the memory for fragmented data and removing fragmentation by re-writing the fragmented data already in MLC into new MLC blocks, may be fixed or variable.

主权项

1. A method of controlling storage of content on a storage device, the method comprising:
in a storage device having a controller in communication with non-volatile memory, wherein the non-volatile memory comprises a first type of non-volatile memory and a second type of non-volatile memory, the controller:
receiving data for storage in the non-volatile memory;upon determining that a fullness of the storage device has reached a proactive defragmentation threshold, only writing sequentially addressed logical groups of received data to the second type of non-volatile memory, wherein only writing sequentially addressed logical groups of received data to the second type of non-volatile memory comprises the controller:
determining if the received data contains at least a threshold number of sequentially addressed logical groups and, when the received data is determined to contain at least the threshold number of sequentially addressed logical groups, bypassing the first type of non-volatile memory and writing the sequentially addressed logical groups of received data directly into the second type of non-volatile memory; andwhen the received data is determined to contain less than the threshold number of sequentially addressed logical groups, writing the received data into the first type of non-volatile memory;andupon determining that the fullness of the storage device has reached a reactive defragmentation threshold automatically defragmenting data already written into the second type of non-volatile memory in response to a triggering event.