Read/write cache device and method persistent in the event of a power failure

摘要

A read/write cache device and method persistent in the event of a power failure are disclosed herein. The read/write cache device includes a meta-information part, a recency/frequency (RF) table part, a mapping table part, and a log area. The meta-information part provides information about whether metadata has integrity and information about the version of metadata stored in two metadata regions. The RF table part provides information about the recency and frequency of each of low-speed segments of a plurality of high-speed and low-speed segments and information about whether each of the low-speed segments is cached, in order to maintain the consistency of the metadata. The mapping table part provides information about a low-speed segment that is cached to each of the high-speed segments. The log area provides changed caching information that is not applied into the mapping table part.

主权项

1. A read/write cache device persistent in an event of a power failure, comprising:
a meta-information part configured to provide information about whether metadata has integrity and information about a version of metadata stored in two metadata regions; a recency/frequency (RF) table part configured to provide an RF value for each low-speed segment to determine the low-speed segment is recently and frequently accessed; a mapping table part configured to provide which low-speed segment each high-speed segment caches; and a log area configured to provide caching information that is not applied to the mapping table part.