Home > Storage > PowerMax and VMAX > Storage Admin > Dell PowerMax: Data Reduction > Extended Data Compression
PowerMax systems include an additional function that will compress already compressed data to gain further capacity savings. The goal of extended data compression (EDC) is to apply additional compression savings to already compressed data. This is accomplished by identifying data that has not been accessed for a set amount of time. The factors that make data a candidate for EDC are the following:
Data that qualifies for EDC is compressed using the Def9_128_SW algorithm and moved to the appropriate compression pool. This is an automated background process within the system. Additional savings are included in the storage group level achieved compression ratio. EDC is only available with PowerMax storage arrays.