US 11,954,027 B2
Parasitic commands for equalizing logical unit capacity in asymmetric multiple actuator hard disk drive
David Hall, Rochester, MN (US); and Ali Khalili, Rochester, MN (US)
Assigned to Western Digital Technologies, Inc., San Jose, CA (US)
Filed by Western Digital Technologies, Inc., San Jose, CA (US)
Filed on Feb. 23, 2022, as Appl. No. 17/678,765.
Prior Publication US 2023/0267076 A1, Aug. 24, 2023
Int. Cl. G06F 12/06 (2006.01); G06F 3/06 (2006.01)
CPC G06F 12/063 (2013.01) [G06F 3/061 (2013.01); G06F 3/0635 (2013.01); G06F 3/0676 (2013.01)] 23 Claims
OG exemplary drawing
 
1. A data storage device comprising:
a first actuator assembly associated with a host-addressable first logical unit and configured to operate on a corresponding first set of disk media surfaces;
a second actuator assembly associated with a host-addressable second logical unit and configured to operate on a corresponding second set of disk media surfaces greater than the first set; and
an electronic controller communicatively coupled with the first actuator assembly and the second actuator assembly, the controller configured to access:
a mapping of logical memory addresses to physical memory locations, the mapping comprising:
a first portion corresponding to the first logical unit associated with the first actuator assembly, wherein the first portion maps the first logical unit to the physical memory locations of the first set of disk media surfaces and a parasitic portion of the second set of disk media surfaces, such that operations by the second actuator assembly on the parasitic portion of the second set of disk media surfaces are attributed to the first logical unit associated with the first actuator assembly, and
a second portion corresponding to the second logical unit, wherein the second portion maps the second logical unit to the physical memory locations of the second set of disk media surfaces exclusive of the parasitic portion of the second set of disk media surfaces, such that operations by the second actuator assembly on the parasitic portion of the second set of disk media surfaces are attributed to the first logical unit associated with the first actuator assembly.