Optimized disk storage defragmentation with swapping capabilities
View Patent ↗There is disclosed apparatus and a method of de-fragmenting file allocations on a disk comprising: determining what pages should be swapped among the various allocations made by the operating system (OS), the OS's file system mapping updated to reflect the swapped pages and a history of the original state prior to any update recorded by the engine, the swaps performed by manipulation of the engine's data structures and/or actually exchanging data on disk where OS visible data is read and written but the original state of each altered page is not directly recorded in the historic log, but instead, a record is additionally logged of the locations of the swapped data so that an image of the OS visible data can be reconstructed prior to time of the de-fragmentation by knowing what data to effectively re-swap and what OS mapping data to effectively restore. The apparatus and method may include the step of incorporating desired close proximity information of various OS visible pages into the algorithm executed by the engine that determines what is actually swapped, in order to reasonable maintain physical close proximity of data allocated by the OS but physically re-mapped by the engine.
1. A method of defragmenting file allocations on a disk, the method comprising:
determining pages to be swapped among various allocations made by an operating system (OS);
swapping determined pages by performing a step from a group of steps consisting of: a) manipulating data structures so as to indicate swapping of pages without actually swapping data between physical locations on a medium; and b) moving data on a medium where OS visible data is read and written;
updating an OS file system mapping to reflect the swapped pages;
logging indications of the swapped pages so that an image of the OS visible data prior to the swapping can be reconstructed, without requiring that each read operation and each write operation be written to a history log; and
incorporating desired close proximity information of various OS visible pages into an algorithm executed by an engine that determines pages to be swapped, in order to reasonably maintain close physical proximity of data allocated by the OS but physically re-mapped by the engine.
2. The method of claim 1 , wherein the method is performed on a computer wherein a history of data is maintained such that the computer can be returned to a state of data from an earlier point in time.
3. The method of claim 1 , wherein the method is performed on a computer wherein a history of data is maintained such that the computer can be returned to a state of data from an earlier point in time.
4. A method according to claim 3 , wherein the historical data is maintained by diverting writes to a different position on the disk so historical data remains in its original location.