| 摘要 |
A persistent cache is implemented in a flash memory that includes a journal section that stores metadata and a low frequency section and a high frequency section that store data entries. Writing new metadata to the persistent cache includes sequentially advancing to a next sector containing an invalid metadata entry, saving a working copy of the sector in RAM, writing metadata corresponding to one or more new data entries in the working copy, and overwriting the sector in the flash memory containing the invalid entry with the working copy. Writes to the low frequency and high frequency sections occur sequentially in the current locations of a low frequency section pointer and a high frequency section pointer, respectively. In a persistent cache, the reconstruction of a non-persistent cache utilizes the metadata entry that has the most recent timestamp.
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