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METHOD TO IMPROVE DATA RELIABILITY IN HDD SYSTEMS USING LOAD/UNLOAD

IP.com Disclosure Number: IPCOM000013381D
Original Publication Date: 2000-Apr-01
Included in the Prior Art Database: 2003-Jun-18
Document File: 1 page(s) / 27K

Publishing Venue

IBM

Abstract

A method of reducing the risk for data loss caused by media damage and/or erasure in load/unload hard disk drives is described, consisting of three parts:

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  METHOD TO IMPROVE DATA RELIABILITY IN HDD SYSTEMS USING LOAD/UNLOAD

   A method of reducing the risk for data loss caused by media damage and/or
erasure in load/unload hard disk drives is described, consisting of three parts:

1) Remap the file LBAs so that the portion of the disk closest to the L/UL
ramp
corresponds to the highest LBAs.

2) Replace all write commands applied against the LBAs corresponding to
the portion of disk real estate closest to the L/UL ramp with
"write/verify"
commands.

3) Execute packscans of the portion of disk real estate closest to the L/UL
ramp during file idle periods. Update the grown defect list with any
detected defective locations.

The rationale for these procedures is based on findings that the data that is
located nearest to the L/UL zone (i.e. nearest the ramp) has the highest risk
in the file for L/UL-related erasure or media removal due to scratching. Item
#1 reduces reliability exposure because customers tend to consume drive space
from low to high LBAs. By mapping the data area nearest the L/UL zone to the
highest LBAs, we postpone exposure to usage of the highest-risk area. The
simpler alternative-- reversing the LBA vs cyl mapping-- would expose the
customer to another problem: the data at the ID extreme which has the highest
linear density (and the greatest propensity for density-related errors) would
be used first.

Additionally, the likelihood of incremental L/UL related damage/erasure tends
to drop as L/UL cycles increases, so the combinat...