Patent ID: 8909887
Filing Date: 2014-12-09
Classification: G06F

Abstract:
1. In a data storage apparatus, a method of managing data fragmentation, the method comprising: receiving an indication that input/output (IO) access to particular data stored within a memory space has exceeded a predefined threshold level; in response to the indication that IO access to the particular data stored within the memory space has exceeded the predefined threshold level, performing a defragmentation evaluation operation; when a result of the defragmentation evaluation operation has a first value, performing a set of data movement operations which moves the particular data from a first set of storage locations of the memory space to a second set of storage locations of the memory space to improve defragmentation of the particular data; and when the result of the defragmentation evaluation operation has a second value which is different than the first value, maintaining the particular data at the first set of storage locations of the memory space; wherein receiving the indication that IO access to the particular data stored within the memory space has exceeded the predefined threshold level includes: processing a historical log of locks imposed on the memory space to ascertain the number of times the particular data stored within the memory space was accessed during a recent time period; wherein the historical log of locks imposed on the memory identifies ranges of extents which were locked during IO operations performed on the memory space; and wherein processing the historical log of locks imposed on the memory space includes updating a set of counters based on the ranges of extents which were locked during the IO operations and which are identified by the historical log of locks.