Patent ID: 8392915
Filing Date: 2013-03-05
Classification: G06F

Abstract:
1. A method of updating an extent map associated with a logical volume manager (LVM), the method comprising: providing in a memory an instance of a first version of the extent map associated with the LVM, the instance referenced by an application; wherein the extent map comprises entries, each extent map entry storing an offset from the beginning of a physical drive or partition that is identified within said each extent map entry; providing a second version of the extent map; determining whether there is a segment in the second version of the extent map which is different from a corresponding segment in the first version of the extent map or for which there is no corresponding segment in the first version of the extent map; and updating the instance in the memory of the first version of the extent map with the segment from the second extent map; wherein during the updating the instance in the memory of the first version of the extent map, the instance of the first version of the extent map remains substantially in the memory such that the entire first version of the extent map need not be replaced by the entire second version of the extent map; and wherein the extent map further comprises an overall version indicator and a plurality of segments, wherein the determining comprises comparing a version indicator of at least one of the segments of the first version of the extent map with a version indicator of at least one of the segments of the second version of the extent map.