Home > Storage > PowerMax and VMAX > Storage Admin > Dell PowerMax: Data Reduction > Fine grain data packing
The Adaptive Compression Engine uses data reduction hardware to process incoming data which is divided into four sections. Each section is compressed in parallel which maximizes the efficiency of the data reduction module. The sum of the four compressed sections is the final compressed size and determines where the data is to be stored. In PowerMax systems where deduplication applies a unique hash id is applied to the compressed data set. This process includes pattern detection, a non-zero allocate function. Pattern detection prevents the allocation of any of the four sections that contain all zeros. This behavior results in an efficient data reduction process that has minimal cost to performance.
Another benefit of dividing the extents into four sections comes when there are partial read or write operations. In this case only the sections that contain the requested data are processed. This means each section can be handled independently.
The efficiency of data compression is measured in terms of the compression ratio. This is the ratio between the original size of the data and its size after being compressed. For example, a 128KB dataset is compressed to 64KB, resulting in a compression ratio of 2:1.