The SAS RAID Enablement feature provides the internal SAS enclosure with 0, 5, 6 and 10 RAID function and auxiliary cache via backplane pluggable daughter cards. The daughter cards contain the RAID function and a 175MByte of write cache. The auxiliary daughter card plugs into a special slot on the planar and provides battery power pack and redundant 175MByte write cache memory for the daughter card.