The DS8000 supports CKD extended address volumes and provides increased storage capacity with 3390 Model A.
3390 Model A is intended as replacement for 3390 Model 3 and 3390 Model 9. Volumes can be converted between 3390 Model 3, 3390 Model 9, and 3390 Model A if the volume sizes are within 3390 Model 3 and 3390 Model 9 limits. 3390 Model 3, 3390 Model 9, and 3390 Model A volumes can be increased in size to their maximum supported sizes. DS8000 and z/OS limit CKD extended address volumes sizes. A 3390 Model A volume has the capacity of 1 - 262668 cylinders (approximately 223.2 GB maximum).
z/VM and z/OS software are required to use extended address volumes. Volume creation and volume expansion is limited to 3390 Model 9 sizes if earlier software has a path group on the DS8000. Volumes larger than 3390 Model 9 do not come online if earlier z/OS software is in use.