Spinpoint M9T Product Manual REV 1.0
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5.5.3 Defect Management
The Spinpoint M9T hard disk drive media is scanned for defects. After defect scanning, the defective sectors
are saved in the defect list. A defect encountered in the manufacturing process is slipped to the next physical
sector location. All logical sector numbers are pushed down to maintain a sequential order of data. The
read/write operation can “slip” over the defective sectors so that the only performance impact is idle time.
5.5.4 Automatic Defect Allocation
The automatic defect allocation feature automatically maps out defective sectors encountered during read sector
or write sector operations. These types of defective sectors are typically caused by grown defects. During write
operations, if write errors are encountered, all sectors within the target servo frame are mapped out. Original
data is transferred and written into designated reserved sector areas determined by the HDD firmware.
5.5.5 SMART
The intent of Self-monitoring, Analysis and Reporting Technology (SMART) is to protect user data and to
minimize the likelihood of unscheduled system downtime that may be caused by unpredictable degradation
and/or device fault. By monitoring and storing critical performance and calibration parameters, SMART
devices attempt to predict the likelihood of near-term degradation or fault condition. Providing the host
system knowledge of a negative reliability condition allows the host system to warn the user of
the impending risk of a data loss and advise the user of appropriate action.
5.5.6 APM
The Automatic Power Management (APM) feature set is an optional feature set that allows the host to select a
power management level. The power management level is specified using a scale from the lowest power
consumption setting to the maximum performance level. Device performance may increase with increasing
power management levels. Device power consumption may increase with increasing power management levels.
This feature is enabled by the Set Features command.
