Data archiving using data compression of a flash copy

摘要

Embodiments of the disclosure relate to archiving data in a storage system. An exemplary embodiment comprises making a flash copy of data in a source volume, compressing data in the flash copy wherein each track of data is compressed into a set of data pages, and storing the compressed data pages in a target volume. Data extents for the target volume may be allocated from a pool of compressed data extents. After each stride worth of data is compressed and stored in the target volume, data may be destaged to avoid destage penalties. Data from the target volume may be decompressed from a flash copy of the target volume in a reverse process to restore each data track, when the archived data is needed. Data may be compressed and uncompressed using a Lempel-Ziv-Welch process.

主权项

1. A computer program product for archiving data in a storage system utilizing a RAID-5 configuration, the computer program product comprising a non-transitory computer readable storage medium having computer readable program code embodied therewith, the computer readable program code comprising:
computer readable program code configured to make a first flash copy of data in a first storage volume while the source volume is off-line, wherein the first flash copy comprises a stride of data including one or more tracks of data and the data includes a previous parity; computer readable program code configured to compress the stride of data, wherein the full stride of data is compressed such that each track of data is compressed into a set of compressed data pages; computer readable program code configured to destage the compressed full stride of data; computer readable program code configured to compute a new parity from the compressed full stride of data without using the data and the previous parity; computer readable program code configured to store the set of compressed data pages in a second storage volume; and computer readable program code configured to uncompress archived data in the second storage volume including:
computer readable program code configured to make a second flash copy of data in the second storage volume, wherein the second flash copy includes the sets of compressed data pages and each set of compressed data pages corresponds to a track of uncompressed data pages in the first volume,computer readable program code configured to uncompress data in each set of compressed data pages in the second flash copy into the corresponding track of uncompressed data, such that the data being uncompressed is uncompressed as a full stride worth, andcomputer readable program code configured to destage the uncompressed data as the full stride worth and to store the uncompressed data in the first storage volume.