SYSTEM, METHOD, AND COMPUTER PROGRAM FOR DATA ARCHIVING USING DATA COMPRESSION OF FLASH COPY (DATA ARCHIVING USING DATA COMPRESSION OF FLASH COPY)

摘要

PROBLEM TO BE SOLVED: To provide a method for archiving and retrieving data of a storage system based upon a flash copy and data compression.SOLUTION: In a source volume, a flash copy of data is generated and the data in the flash copy is compressed. Each track of data is compressed into a data page set, and compressed data pages are stored in a target volume. A data extent is allocated to the target volume from a pool of compressed data extents. After each stride worth of data is compressed and stored in the target volume, the data is destaged to avoid a destage penalty. When the archived data is needed, data from the target volume is decompressed to restore each data block. The data is compressed and uncompressed using an LZW (Lempel-Ziv-Welch) process.