Patent ID: 9323772
Filing Date: 2016-04-26
CPC Classification: G06F

Claim Text:
1. A host comprising: an interface configured to relay data exchange with a storage device; and a file system module configured to perform a segment cleaning process by performing operations comprising selecting victim segments from a plurality of segments stored in the storage device, discovering live blocks in the victim segments, writing back the discovered live blocks to the storage device through the interface, and returning the victim segments to a free area, wherein the file system module is further configured to perform operations comprising calculating victim points for segments included in a first segment group using a first victim point calculation formula, calculating victim points for segments included in a second segment group using a second victim point calculation formula, calculating victim points for segments included in a third segment group using the second victim point calculation formula and selecting the victim segments based on the victim points, wherein the second segment group consists of segments which comprise data written when the data included in the segments of the first segment group is updated, the third segment group comprises the written-back data, the first victim point calculation formula uses a proportion of live blocks relative to the total number of blocks included in a segment and an age calculated using a modification time of a last modified one of the blocks included in the segment, and the second victim point calculation formula uses the proportion of live blocks relative to the total number of blocks included in a segment, but does not use the age calculated using a modification time of a last modified one of the blocks included in the segment.