The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Nov. 18, 2014
Filed:
Sep. 27, 2011
Zvonimir Z. Bandic, San Jose, CA (US);
Yuval Cassuto, Lausanne, CH;
Jonathan Darrel Coker, Rochester, MN (US);
Cyril Guyot, San Jose, CA (US);
Marco Sanvido, Belmont, CA (US);
Zvonimir Z. Bandic, San Jose, CA (US);
Yuval Cassuto, Lausanne, CH;
Jonathan Darrel Coker, Rochester, MN (US);
Cyril Guyot, San Jose, CA (US);
Marco Sanvido, Belmont, CA (US);
HGST Netherlands B.V., Amsterdam, NL;
Abstract
Methods are described that allow disk drives, such as shingle-written magnetic recording (SMR) drives, to recover an Indirection Address Table mapping of LBAs to PBAs after an emergency power off (EPO). Indirection Address Table (IAT) snapshots are periodically written inline with user data stores, and in one embodiment Cumulative Delta Lists (CDLs) with incremental address update information are stored between snapshots. In an embodiment of the invention, when an imminent loss of power is detected, the current CDL, covering IAT updates not yet written to disk, is saved to a nonvolatile memory. The IAT snapshots combined with the set of CDLs provide the information needed to recreate the current Indirection Address Table when power is restored after an emergency power loss. In an alternative embodiment the CDL is obviated by including metadata in the sector that encodes the address indirection mapping and the last snapshot ID.