Robert W Caldwell

US Patent:

20170249969, Aug 31, 2017

Filed:

Dec 21, 2016

Appl. No.:

15/387164

Inventors:

- Aliso Viejo CA, US
Robert CALDWELL - Orlando FL, US

International Classification:

G11B 20/12
G06F 3/06
G06F 12/0802
G06F 12/02

Abstract:

Methods, devices and systems are provided for making a shingled magnetic recording (SMR) hard disk drive operate with similar random access characteristics of a conventional hard drive despite the SMR disk having strict sequential write requirements. A virtual space manager manages a virtual address space, which is visible to a host system, and maps virtual addresses to logical addresses on the SMR disk. A logical space manager controls the placement of data on the SMR disk and ensures that writes to the disk comply with the sequential write requirements. The disk is subdivided into a plurality of stripes each comprising one or more blocks. When a block located within a stripe is to be rewritten with new data, the entire stripe is read from the SMR disk into a memory of the system, the stripe is modified in the memory to replace the previous data stored in the block with the new data, and the modified stripe is written to a new, next available stripe on the disk.