METHODS AND SYSTEMS FOR PRESERVING BLOCKS THAT ARE NEITHER OBSOLETE NOR COLD

摘要

A storage device made up of multiple storage media is configured such that one such media serves as a cache for data stored on another of such media. The device includes a controller configured to manage the cache by consolidating information concerning obsolete data stored in the cache with information concerning data no longer desired to be stored in the cache, and erase segments of the cache containing one or more of the blocks of obsolete data and the blocks of data that are no longer desired to be stored in the cache to produce reclaimed segments of the cache.

主权项

1. A method for a flash cache that stores a first group of one or more segments and a second group of one or more segments, each of the segments storing zero or more blocks, the method comprising:
for the first group of one or more segments, determining which of the blocks are obsolete, and which of the blocks are cold, wherein the obsolete blocks will no longer be accessed, and the cold blocks will not likely be accessed; and copying, from the first group of one or more segments to the second group of one or more segments, all of the blocks that are neither obsolete nor cold.