needs to allocate the wpa may maintain indicators e g pointers that allow it to determine a current fill location for one or more columns in an active write device unit e g a flash memory line or a group of flash memory die a wpa may also be aware of the number of free grain locations in each column the total number of grain locations and or the number of used or unavailable grain locations a wpa may determine which column e g portion of flash memory storage new grains may be allocated to at the same time or at a different time a wpa may also determine a location or locations to send data for generation of a parity bit and or storage of a parity bit or other error correcting code e g a resource location to xor data once the allocated grains are identified and the location of parity storage is identified a wpa may return two identifiers e g sram offsets to the appropriate compression unit e g based on an id or indicator provided with a grain allocation request a compression unit may use the two indicators to send the data to both locations e g the allocated grains for data storage as well as xor parity storage in some embodiments a wpa may further.