Patent ID: 8914597

Claim:
A computer implemented method for archiving data in a storage system utilizing a RAID-5 configuration, comprising: making a first flash copy of data in a first storage volume while the first storage 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; compressing 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; destaging the compressed full stride of data; computing a new parity from the compressed full stride of data without using the data and the previous parity; storing the set of compressed data pages into a second storage volume; uncompressing archived data in the second storage volume by: making 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, uncompressing 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, and destaging the uncompressed data as the full stride worth and storing the uncompressed data in the first storage volume.