Patent ID: 8001165
Filing Date: 2011-08-16
Classification: G06F

Abstract:
1. A method comprising: indicating a first bitmap image associated with a file allocation table of a file system as a last known good bitmap image, the file allocation table defining storage segments allocated to a file in the file system, the first bitmap image adapted to store an allocation bit for each storage segment allocated to the file in the file system; synchronizing a second bitmap image to the first bitmap image resulting in the second bitmap image and the first bitmap image identically indicating each storage segment allocated to the file in the file system, wherein the second bitmap image is to be modified and the first bitmap image is to remain unchanged when an operation to change the file system is performed; performing an operation to change a portion of the file system, the operation comprising deleting the file in the file system, wherein deleting the file in the file system does not require a change to the file allocation table of the file system; modifying the second bitmap image to indicate that each storage segment allocated to the file in the file system is free for overwriting as result of deleting the file in the file system; after the operation is completed, indicating that the second bitmap image is the last known good bitmap image; and synchronizing the first bitmap image to the second bitmap.